USE flag index

What are USE flags?
For more information on the idea behind USE flags and how to use them, please see our documentation.

Global USE flags

Flag Description
X Add support for X11
Xaw3d Add support for the 3d athena widget set
a52 Enable support for decoding ATSC A/52 streams used in DVD
aac Enable support for MPEG-4 AAC Audio
aalib Add support for media-libs/aalib (ASCII-Graphics Library)
accessibility Add support for accessibility (eg 'at-spi' library)
acl Add support for Access Control Lists
acpi Add support for Advanced Configuration and Power Interface
adns Add support for asynchronous DNS resolution
afs Add OpenAFS support (distributed file system)
alsa Add support for media-libs/alsa-lib (Advanced Linux Sound Architecture)
ao Use libao audio output library for sound playback
apache2 Add Apache2 support
aqua Include support for the Mac OS X Aqua (Carbon/Cocoa) GUI
asm Enable using assembly for optimization
atm Enable Asynchronous Transfer Mode protocol support
apparmor Enable support for the AppArmor application security system
appindicator Build in support for notifications using the libindicate or libappindicator plugin
audiofile Add support for libaudiofile where applicable
audit Enable support for Linux audit subsystem using sys-process/audit
avif Add AV1 Image Format (AVIF) support
bash-completion Enable bash-completion support
berkdb Add support for sys-libs/db (Berkeley DB for MySQL)
bidi Enable bidirectional language support
big-endian Big-endian toolchain support
bindist Flag to enable or disable options for prebuilt (GRP) packages (eg. due to licensing issues)
blas Add support for the virtual/blas numerical library
bluetooth Enable Bluetooth Support
branding Enable Gentoo specific branding
brotli Enable Brotli compression support
build !!internal use only!! DO NOT SET THIS FLAG YOURSELF!, used for creating build images and the first half of bootstrapping [make stage1]
bzip2 Enable bzip2 compression support
cairo Enable support for the cairo graphics library
calendar Add support for calendars (not using mcal!)
caps Use Linux capabilities library to control privilege
cdb Add support for the CDB database engine from the author of qmail
cdda Add Compact Disk Digital Audio (Standard Audio CD) support
cddb Access cddb servers to retrieve and submit information about compact disks
cdinstall Copy files from the CD rather than asking the user to copy them, mostly used with games
cdr Add support for CD writer hardware
cgi Add CGI script support
cjk Add support for Multi-byte character languages (Chinese, Japanese, Korean)
clamav Add support for Clam AntiVirus software (usually with a plugin)
colord Support color management using x11-misc/colord
connman Add support for net-misc/connman
coreaudio Build the CoreAudio driver on Mac OS X systems
cracklib Support for cracklib strong password checking
crypt Add support for encryption -- using mcrypt or gpg where applicable
css Enable reading of encrypted DVDs
cuda Enable NVIDIA CUDA support (computation on GPU)
cups Add support for CUPS (Common Unix Printing System)
curl Add support for client-side URL transfer library
custom-cflags Build with user-specified CFLAGS (unsupported)
cvs Enable CVS (Concurrent Versions System) integration
cxx Build support for C++ (bindings, extra libraries, code generation, ...)
dbi Enable dev-db/libdbi (database-independent abstraction layer) support
dbm Add support for generic DBM databases
dbus Enable dbus support for anything that needs it (gpsd, gnomemeeting, etc)
debug Enable extra debug codepaths, like asserts and extra output. If you want to get meaningful backtraces see https://wiki.gentoo.org/wiki/Project:Quality_Assurance/Backtraces
dedicated Add support for dedicated game servers (some packages do not provide clients and servers at the same time)
dga Add DGA (Direct Graphic Access) support for X
dist-kernel Enable subslot rebuilds on Distribution Kernel upgrades
djvu Support DjVu, a PDF-like document format esp. suited for scanned documents
doc Add extra documentation (API, Javadoc, etc). It is recommended to enable per package instead of globally
dri Enable direct rendering: used for accelerated 3D and some 2D, like DMA
dts Enable DTS Coherent Acoustics decoder support
dv Enable support for a codec used by many camcorders
dvb Add support for DVB (Digital Video Broadcasting)
dvd Add support for DVDs
dvdr Add support for DVD writer hardware (e.g. in xcdroast)
eds Enable support for Evolution-Data-Server (EDS)
egl Enable EGL (Embedded-System Graphics Library, interfacing between windowing system and OpenGL/GLES) support
elogind Enable session tracking via sys-auth/elogind
emacs Add support for GNU Emacs
emboss Add support for the European Molecular Biology Open Software Suite
encode Add support for encoding of audio or video files
examples Install examples, usually source code
exif Add support for reading EXIF headers from JPEG and TIFF images
expat Enable the use of dev-libs/expat for XML parsing
fam Enable FAM (File Alteration Monitor) support
fastcgi Add support for the FastCGI interface
fbcon Add framebuffer support for the console, via the kernel
ffmpeg Enable ffmpeg/libav-based audio/video codec support
fftw Use FFTW library for computing Fourier transforms
filecaps Use Linux file capabilities to control privilege rather than set*id (this is orthogonal to USE=caps which uses capabilities at runtime e.g. libcap)
firebird Add support for the Firebird relational database
flac Add support for FLAC: Free Lossless Audio Codec
fltk Add support for the Fast Light Toolkit gui interface
fontconfig Support for configuring and customizing font access via media-libs/fontconfig
fortran Add support for fortran
freetds Add support for the TDS protocol to connect to MSSQL/Sybase databases
ftp Add FTP (File Transfer Protocol) support
gd Add support for media-libs/gd (to generate graphics on the fly)
gdbm Add support for sys-libs/gdbm (GNU database libraries)
geoip Add geoip support for country and city lookup based on IPs
geolocation Enable physical position determination
ggi Add support for media-libs/libggi (non-X video api/drivers)
gif Add GIF image support
gimp Build a plugin for the GIMP
git Enable git (version control system) support
gles2 Enable GLES 2.0 (OpenGL for Embedded Systems) support (independently of full OpenGL, see also: gles2-only)
gles2-only Use GLES 2.0 (OpenGL for Embedded Systems) or later instead of full OpenGL (see also: gles2)
glut Build an OpenGL plugin using the GLUT library
gmp Add support for dev-libs/gmp (GNU MP library)
gnome Add GNOME support
gnome-keyring Enable support for storing passwords via gnome-keyring
gnuplot Enable support for gnuplot (data and function plotting)
gnutls Prefer net-libs/gnutls as SSL/TLS provider (ineffective with USE=-ssl)
gphoto2 Add digital camera support
gpm Add support for sys-libs/gpm (Console-based mouse driver)
gps Add support for Global Positioning System
graphicsmagick Build and link against GraphicsMagick instead of ImageMagick (requires USE=imagemagick if optional)
graphviz Add support for the Graphviz library
gsl Use the GNU scientific library for calculations
gsm Add support for the gsm lossy speech compression codec
gstreamer Add support for media-libs/gstreamer (Streaming media)
gtk Add support for x11-libs/gtk+ (The GIMP Toolkit)
gtk-doc Build and install gtk-doc based developer documentation for dev-util/devhelp, IDE and offline use
gui Enable support for a graphical user interface
guile Add support for the guile Scheme interpreter
gzip Compress files with Lempel-Ziv coding (LZ77)
handbook Enable handbooks generation for packages by KDE
hardened Activate default security enhancements for toolchain (gcc, glibc, binutils)
hddtemp Enable monitoring of hdd temperature (app-admin/hddtemp)
hdf5 Add support for the Hierarchical Data Format v5
headers-only Install only C headers instead of whole package. Mainly used by sys-devel/crossdev for toolchain bootstrap.
heif Enable support for ISO/IEC 23008-12:2017 HEIF/HEIC image format
hscolour Include coloured haskell sources to generated documentation (dev-haskell/hscolour)
http2 Enable support for the HTTP/2 protocol
ibm Add support for IBM ppc64 specific systems
iconv Enable support for the iconv character set conversion library
icu Enable ICU (Internationalization Components for Unicode) support, using dev-libs/icu
idn Enable support for Internationalized Domain Names
ieee1394 Enable FireWire/iLink IEEE1394 support (dv, camera, ...)
imagemagick Enable optional support for the ImageMagick or GraphicsMagick image converter
imap Add support for IMAP (Internet Mail Application Protocol)
imlib Add support for imlib, an image loading and rendering library
infiniband Enable Infiniband RDMA transport support
initramfs Include kernel modules in the initramfs, and re-install the kernel (only effective for distribution kernels)
inotify Enable inotify filesystem monitoring support
introspection Add support for GObject based introspection
iodbc Add support for iODBC library
ios Enable support for Apple's iDevice with iOS operating system (iPad, iPhone, iPod, etc)
ipod Enable support for iPod device access
ipv6 Add support for IP version 6
jack Add support for the JACK Audio Connection Kit
java Add support for Java
javascript Enable javascript support
jbig Enable jbig-kit support for tiff, Hylafax, ImageMagick, etc
jemalloc Use dev-libs/jemalloc for memory management
jit Enable just-in-time compilation for improved performance. May prevent use of some PaX memory protection features in Gentoo Hardened.
joystick Add support for joysticks in all packages
jpeg Add JPEG image support
jpeg2k Support for JPEG 2000, a wavelet-based image compression format
jpegxl Add JPEG XL image support
kde Add support for software made by KDE, a free software community
kerberos Add kerberos support
keyring Enable support for freedesktop.org Secret Service API password store
ladspa Enable the ability to support ladspa plugins
lame Prefer using LAME libraries for MP3 encoding support
lapack Add support for the virtual/lapack numerical library
lash Add LASH Audio Session Handler support
latex Add support for LaTeX (typesetting package)
lcms Add lcms support (color management engine)
ldap Add LDAP support (Lightweight Directory Access Protocol)
libass SRT/SSA/ASS (SubRip / SubStation Alpha) subtitle support
libcaca Add support for colored ASCII-art graphics
libedit Use the libedit library (replacement for readline)
libffi Enable support for Foreign Function Interface library
libnotify Enable desktop notification support
libsamplerate Build with support for converting sample rates using libsamplerate
libwww Add libwww support (General purpose WEB API)
lirc Add support for lirc (Linux's Infra-Red Remote Control)
livecd !!internal use only!! DO NOT SET THIS FLAG YOURSELF!, used during livecd building
llvm-libunwind Use sys-libs/llvm-libunwind instead of sys-libs/libunwind
lm-sensors Add linux lm-sensors (hardware sensors) support
lto Enable Link-Time Optimization (LTO) to optimize the build
lua Enable Lua scripting support
lz4 Enable support for lz4 compression (as implemented in app-arch/lz4)
lzip Enable support for lzip compression
lzma Support for LZMA compression algorithm
lzo Enable support for lzo compression
m17n-lib Enable m17n-lib support
mad Add support for mad (high-quality mp3 decoder library and cli frontend)
magic Add support for file type detection via magic bytes (usually via libmagic from sys-apps/file)
maildir Add support for maildir (~/.maildir) style mail spools
man Build and install man pages
matroska Add support for the matroska container format (extensions .mkv, .mka and .mks)
mbox Add support for mbox (/var/spool/mail) style mail spools
memcached Add support for memcached
mhash Add support for the mhash library
mikmod Add libmikmod support to allow playing of SoundTracker-style music files
milter Add sendmail mail filter (milter) support
minimal Install a very minimal build (disables, for example, plugins, fonts, most drivers, non-critical features)
mmap Add mmap (memory map) support
mms Support for Microsoft Media Server (MMS) streams
mng Add support for libmng (MNG images)
modplug Add libmodplug support for playing SoundTracker-style music files
modules Build the kernel modules
modules-compress Install compressed kernel modules (if kernel config enables module compression)
modules-sign Cryptographically sign installed kernel modules (requires CONFIG_MODULE_SIG=y in the kernel)
mono Build Mono bindings to support dotnet type stuff
motif Add support for the Motif toolkit
mp3 Add support for reading mp3 files
mp4 Support for MP4 container format
mpeg Add libmpeg3 support to various packages
mpi Add MPI (Message Passing Interface) layer to the apps that support it
mplayer Enable mplayer support for playback or encoding
mssql Add support for Microsoft SQL Server database
mtp Enable support for Media Transfer Protocol
multilib On 64bit systems, if you want to be able to compile 32bit and 64bit binaries
musepack Enable support for the musepack audio codec
musicbrainz Lookup audio metadata using MusicBrainz community service (musicbrainz.org)
mysql Add mySQL Database support
mysqli Add support for the improved mySQL libraries
nas Add support for network audio sound
native-extensions Build native (e.g. C, Rust) extensions in addition to pure (e.g. Python) code (usually speedups)
ncurses Add ncurses support (console display library)
neXt Enable neXt toolkit
netcdf Enable NetCDF data format support
networkmanager Enable net-misc/networkmanager support
nis Support for NIS/YP services
nls Add Native Language Support (using gettext - GNU locale utilities)
nntp Add support for newsgroups (Network News Transfer Protocol)
nocd Install all files required to run the application without a CD mounted
nsplugin Build plugin for browsers supporting the Netscape plugin architecture (that is almost any modern browser)
nvenc Add support for NVIDIA Encoder/Decoder (NVENC/NVDEC) API for hardware accelerated encoding and decoding on NVIDIA cards (requires x11-drivers/nvidia-drivers)
ocaml Add support/bindings for the Ocaml language
ocamlopt Enable ocamlopt support (ocaml native code compiler) -- Produces faster programs (Warning: you have to disable/enable it at a global scale)
oci8 Add Oracle 8 Database Support
oci8-instant-client Use dev-db/oracle-instantclient-basic as Oracle provider instead of requiring a full Oracle server install
odbc Add ODBC Support (Open DataBase Connectivity)
offensive Enable potentially offensive items in packages
ofx Enable support for importing (and exporting) OFX (Open Financial eXchange) data files
ogg Add support for the Ogg container format (commonly used by Vorbis, Theora and flac)
openal Add support for the Open Audio Library
opencl Enable OpenCL support (computation on GPU)
openexr Support for the OpenEXR graphics file format
opengl Add support for OpenGL (3D graphics)
openmp Build support for the OpenMP (support parallel computing), requires >=sys-devel/gcc-4.2 built with USE="openmp"
opentype-compat Convert BDF and PCF bitmap fonts to OTB wrapper format
opus Enable Opus audio codec support
oracle Enable Oracle Database support
orc Use dev-lang/orc for just-in-time optimization of array operations
osc Enable support for Open Sound Control
oss Add support for OSS (Open Sound System)
otf Install OpenType font versions
pam Add support for PAM (Pluggable Authentication Modules) - DANGEROUS to arbitrarily flip
pch Enable precompiled header support for faster compilation at the expense of disk space and memory
pcmcia Add support for PCMCIA slots/devices found on laptop computers
pcre Add support for Perl Compatible Regular Expressions
pda Add support for portable devices
pdf Add general support for PDF (Portable Document Format), this replaces the pdflib and cpdflib flags
perl Add optional support/bindings for the Perl language
php Include support for the PHP language
pie Build programs as Position Independent Executables (a security hardening technique)
plasma Build optional KDE plasma addons
plotutils Add support for plotutils (library for 2-D vector graphics)
png Add support for libpng (PNG images)
policykit Enable PolicyKit (polkit) authentication support
portaudio Add support for the crossplatform portaudio audio API
posix Add support for POSIX-compatible functions
postgres Add support for the postgresql database
postscript Enable support for the PostScript language (often with ghostscript-gpl or libspectre)
ppds Add support for automatically generated ppd (printing driver) files
prefix Defines if a Gentoo Prefix offset installation is used
profile Add support for software performance analysis (will likely vary from ebuild to ebuild)
pulseaudio Add sound server support via media-libs/libpulse (may be PulseAudio or PipeWire)
python Add optional support/bindings for the Python language
qdbm Add support for the qdbm (Quick Database Manager) library
qmail-spp Add support for qmail SMTP plugins
qt5 Add support for the Qt 5 application and UI framework
qt6 Add support for the Qt 6 application and UI framework
quicktime Add support for OpenQuickTime
radius Add support for RADIUS authentication
raw Add support for raw image formats
rdp Enables RDP/Remote Desktop support
readline Enable support for libreadline, a GNU line-editing library that almost everyone wants
recode Enable support for the GNU recode library
rss Enable support for RSS feeds
ruby Add support/bindings for the Ruby language
samba Add support for SAMBA (Windows File and Printer sharing)
sasl Add support for the Simple Authentication and Security Layer
savedconfig Use this to restore your config from /etc/portage/savedconfig ${CATEGORY}/${PN}. Make sure your USE flags allow for appropriate dependencies
scanner Add support for scanner hardware (e.g. build the sane frontend in kdegraphics)
screencast Enable support for remote desktop and screen cast using PipeWire
sctp Support for Stream Control Transmission Protocol
sdl Add support for Simple Direct Layer (media library)
seccomp Enable seccomp (secure computing mode) to perform system call filtering at runtime to increase security of programs
secureboot Automatically sign efi executables using user specified key
selinux !!internal use only!! Security Enhanced Linux support, this must be set by the selinux profile or breakage will occur
semantic-desktop Cross-KDE support for semantic search and information retrieval
session Add persistent session support
sid Enable SID (Commodore 64 audio) file support
skey Enable S/Key (Single use password) authentication support
slang Add support for the slang text display library (it's like ncurses, but different)
smartcard Enable smartcard support
smp Enable support for multiprocessors or multicore systems
snappy Enable support for Snappy compression (as implemented in app-arch/snappy)
sndfile Add support for libsndfile
snmp Add support for the Simple Network Management Protocol if available
soap Add support for SOAP (Simple Object Access Protocol)
sockets Add support for tcp/ip sockets
socks5 Add support for the socks5 proxy
sound Enable sound support
source Zip the sources and install them
sox Add support for Sound eXchange (SoX)
speech Enable text-to-speech support
speex Add support for the speex audio codec (used for speech)
spell Add dictionary support
split-usr Enable behavior to support maintaining /bin, /lib*, /sbin and /usr/sbin separately from /usr/bin and /usr/lib*
sqlite Add support for sqlite - embedded sql database
ssl Add support for SSL/TLS connections (Secure Socket Layer / Transport Layer Security)
startup-notification Enable application startup event feedback mechanism
static !!do not set this during bootstrap!! Causes binaries to be statically linked instead of dynamically
static-libs Build static versions of dynamic libraries as well
strip Allow symbol stripping to be performed by the ebuild for special files
subversion Enable subversion (version control system) support
suid Enable setuid root program(s)
svg Add support for SVG (Scalable Vector Graphics)
svga Add support for SVGAlib (graphics library)
symlink Force kernel ebuilds to automatically update the /usr/src/linux symlink
syslog Enable support for syslog
systemd Enable use of systemd-specific libraries and features like socket activation or session tracking
szip Use the szip compression library
taglib Enable tagging support with taglib
tcl Add support the Tcl language
tcmalloc Use the dev-util/google-perftools libraries to replace the malloc() implementation with a possibly faster one
tcpd Add support for TCP wrappers
telemetry Send anonymized usage information to upstream so they can better understand our users
test Enable dependencies and/or preparations necessary to run tests (usually controlled by FEATURES=test but can be toggled independently)
test-rust Enable important test dependencies that require Rust toolchain
theora Add support for the Theora Video Compression Codec
threads Add threads support for various packages. Usually pthreads
tidy Add support for HTML Tidy
tiff Add support for the TIFF image format
time64 Use 64-bit time_t type instead of the regular 32-bit type. This flag is forced on time64 profiles, and masked elsewhere. It should be only used when detection of type width is not possible (e.g. for SRC_URI)
timidity Build with Timidity++ (MIDI sequencer) support
tk Add support for Tk GUI toolkit
truetype Add support for FreeType and/or FreeType2 fonts
ttf Install TrueType font versions
udev Enable virtual/udev integration (device discovery, power and storage device support, etc)
udisks Enable storage management support (automounting, volume monitoring, etc)
uefi Enable support for the Unified Extensible Firmware Interface
unicode Add support for Unicode
unwind Add support for call stack unwinding and function name resolution
upnp Enable UPnP port mapping support
upnp-av Enable UPnP audio/video streaming support
upower Enable power management support
usb Add USB support to applications that have optional USB support (e.g. cups)
v4l Enable support for video4linux (using linux-headers or userspace libv4l libraries)
vaapi Enable Video Acceleration API for hardware decoding
vala Enable bindings for dev-lang/vala
valgrind Enable annotations for accuracy. May slow down runtime slightly. Safe to use even if not currently using dev-debug/valgrind
vanilla Do not add extra patches which change default behaviour; DO NOT USE THIS ON A GLOBAL SCALE as the severity of the meaning changes drastically
vcd Video CD support
vdpau Enable the Video Decode and Presentation API for Unix acceleration interface
verify-sig Verify upstream signatures on distfiles
vhosts Add support for installing web-based applications into a virtual-hosting environment
videos Install optional video files (used in some games)
vim-syntax Pulls in related vim syntax scripts
vnc Enable VNC (remote desktop viewer) support
vorbis Add support for the OggVorbis audio codec
vulkan Add support for 3D graphics and computing via the Vulkan cross-platform API
wavpack Add support for wavpack audio compression tools
wayland Enable dev-libs/wayland backend
webkit Add support for the WebKit HTML rendering/layout engine
webp Add support for the WebP image format
wifi Enable wireless network functions
wmf Add support for the Windows Metafile vector image format
wxwidgets Add support for wxWidgets/wxGTK GUI toolkit
x264 Enable h264 encoding using x264
xattr Add support for extended attributes (filesystem-stored metadata)
xcb Support the X C-language Binding, a replacement for Xlib
xcomposite Enable support for the Xorg composite extension
xemacs Add support for XEmacs
xface Add xface support used to allow a small image of xface format to be included in an email via the header 'X-Face'
xft Build with support for XFT font renderer (x11-libs/libXft)
xine Add support for the XINE movie libraries
xinerama Add support for querying multi-monitor screen geometry through the Xinerama API
xinetd Add support for the xinetd super-server
xml Add support for XML files
xmlrpc Support for xml-rpc library
xmp Enable support for Extensible Metadata Platform (Adobe XMP)
xmpp Enable support for Extensible Messaging and Presence Protocol (XMPP) formerly known as Jabber
xosd Sends display using the X On Screen Display library
xpm Add support for XPM graphics format
xscreensaver Add support for XScreenSaver extension
xv Add in optional support for the Xvideo extension (an X API for video playback)
xvid Add support for xvid.org's open-source mpeg-4 codec
zeroconf Support for DNS Service Discovery (DNS-SD)
zip Enable support for ZIP archives
zlib Add support for zlib compression
zsh-completion Enable zsh completion support
zstd Enable support for ZSTD compression

Local USE flags

acct-user

git

gitea Set home directory for git hosting via www-apps/gitea.
gitolite Set home directory for git hosting via dev-vcs/gitolite or dev-vcs/gitolite-gentoo.

vdr

graphlcd Prepare group membership for media-plugins/vdr-graphlcd.
legacy-homedir Keep old home directory /var/vdr of an existing installation. When this useflag is cleared, the home directory is switched to FHS conformant /var/lib/vdr
remote Prepare group membership for media-plugins/vdr-remote.
serial Prepare group membership for media-plugins/vdr-serial.

app-accessibility

at-spi2-core

dbus-broker Use DBus broker implementation instead of default DBus daemon

brltty

api build brltty's application program interface
beeper support the console tone generator
fm support for the sound card synthesizer
louis Use braille translator dev-libs/liblouis
midi support the musical instrument digital interface
pcm support for sound card digital audio

emacspeak

espeak Adds support for the espeak tts engine

espeak-ng

async Enables asynchronous commands
klatt Enables Klatt formant synthesis and implementation
l10n_ru Builds extended Russian Dictionary file
l10n_zh Builds extended Chinese (Mandarin and Cantonese) Dictionary files
man Builds and installs manpage with app-text/ronn-ng
mbrola Adds support for mbrola voices

flite

voices Install synthetic voices

freetts

jsapi build Java Speech API (JSAPI)
mbrola Adds support for mbrola voices

orca

braille Enable braille support

speech-dispatcher

espeak Adds support for espeak-ng speech engine
flite Adds support for flite speech engine

app-admin

clsync

apidoc Provide doxygen generated API docs.
cgroups Use cgroups to limit /dev access.
clsync Build clsync binary. Most likely you want it. However it is possible to build only libclsync without clsync itself.
cluster Enable clustering support (allows master-master clsync on multiple hosts). Not fully implemented yet.
control-socket Enable AF_UNIX control socket support.
extra-debug Enable extra debugging. This will hurt performance badly. Be ready for tons of output.
extra-hardened Enable extra security checks. This will hurt performance.
gio Enable GIO for FS monitoring (glib based alternative to inotify interface, not recommended; if both are compiled, may be selected at runtime).
highload-locks Allows to use spinlocks for short delays instead of mutexes, but only on SMP systems.
namespaces Enable namespaces isolation.
socket-library Build the control and monitoring socket library: libclsync.

conky

apcupsd Enable support for sys-power/apcupsd
bundled-toluapp Enable support for bundled toluapp. This only makes sense in combination with the lua-* flags
cmus Enable monitoring of music played by media-sound/cmus
colour-name-map Include mappings of colour name
extras Enable syntax highlighting for app-editors/nanoand app-editors/vim
ical Enable support for events from iCalendar (RFC 5545) files using dev-libs/libical
intel-backlight Enable support for Intel backlight
iostats Enable support for per-task I/O statistics
irc Enable support for displaying everything from an irc channel using net-libs/libircclient
lua-cairo Enable if you want Lua Cairo bindings
lua-cairo-xlib Enable support for Cairo and Xlib interoperability for Lua
lua-imlib Enable if you want Lua Imlib2 bindings
lua-rsvg Enable if you want Lua RSVG bindings
math Enable support for glibc's libm math library
moc Enable monitoring of music played by media-sound/moc
mouse-events Enable support for mouse events"
mpd Enable monitoring of music controlled by media-sound/mpd
nvidia Enable reading of nvidia card temperature sensors via x11-drivers/nvidia-drivers
portmon Enable support for tcp (ip4) port monitoring
thinkpad Enable support for IBM/Lenovo notebooks
webserver Enable support to act as a webserver serving conkys output using net-libs/libmicrohttpd
xinput Enable support for Xinput 2 (slow)
xmms2 Enable monitoring of music played by media-sound/xmms2

conserver

freeipmi Compile in FreeIPMI support via sys-libs/freeipmi

diradm

automount Support for automount data in LDAP
irixpasswd Support for storing separate IRIX passwords

doas

persist Adds support for "persist" feature (experimental)

gkrellm

X Build both the X11 gui (gkrellm) and the server (gkrellmd). Disabling this flag builds the server only
gnutls Enable SSL support for mail checking with net-libs/gnutls (overrides 'ssl' USE flag)
lm-sensors Enable monitoring sensors via sys-apps/lm-sensors
ntlm Enable NTLM authentication for mail checking with net-libs/libntlm
ssl Enable SSL support for mail checking with dev-libs/openssl

gtkdiskfree

gtk2 Support GTK+ 2.x instead of GTK+ 3.x

hddtemp

network-cron Monthly cronjob to update hddtemp.db.

keepass

aot Generate native code at build time, rather than runtime.

keepassxc

autotype Add support to autotype the passwords into other applications
browser Enables browser plugin support
keeshare Enable KeeShare sharing integration
network Enable network support
yubikey Enable database unlocking via hardware keys supporting YubiKey-style HMAC-SHA1 protocol

lnav

pcap Enable support for pcap files.

logcheck

cron Adds file to enable hourly cron job to run logcheck"

logrotate

acl Installs acl support
cron Installs cron file
selinux Installs Security Enhanced Linux support

logstash-bin

x-pack Enable additional features (may need a license)

openrc-settingsd

systemd Use the versions of dbus and polkit files provided by sys-apps/systemd

pass

X Use x11-misc/xclip to copy passwords to the clipboard.
dmenu Add support for x11-misc/dmenu with the 'passmenu' program.
git Use dev-vcs/git for password revisions.
importers Allow importing passwords from other password managers using various contributed scripts.

pass-otp

qrcode Add support for qrcodes using media-gfx/qrencode

passwordsafe

qr Enable QR code password display
xml Enable XML import support
yubikey Enable support for Yubikey

perl-cleaner

pkgcore Use sys-apps/pkgcore instead of sys-apps/portage and app-portage/portage-utils.

puppet

augeas Enable augeas support
diff Enable diff support
hiera Enable hiera support
rrdtool Enable rrdtool support
shadow Enable shadow support

puppet-agent

puppetdb Adds puppetdb support

puppetserver

puppetdb Adds support for connecting to puppetdb

pwgen

livecd Install init script for root password scrambling on boot

rsyslog

clickhouse Build the ClickHouse output module (requires net-misc/curl)
curl Enable http_request() function in RainerScript (requires net-misc/curl)
dbi Build the general database output module (requires dev-db/libdbi)
elasticsearch Build the Elasticsearch output module (requires net-misc/curl)
gcrypt Add support for encrypted log files using dev-libs/libgcrypt
gnutls Build the GnuTLS network stream driver (requires net-libs/gnutls)
imhttp Build the http input module (requires www-servers/civetweb)
impcap Build the pcap input module (requires net-libs/libpcap)
kafka Build the Apache Kafka input/output module (requires dev-libs/librdkafka)
kerberos Build the GSSAPI input and output module (requires virtual/krb5)
kubernetes Build the kubernetes modify plugin (requires net-misc/curl)
mdblookup Build the MaxMind DB lookup message modify plugin using dev-libs/libmaxminddb
mongodb Build the MongoDB output module (requires dev-libs/mongo-c-driver)
mysql Build the MySQL database output module (requires virtual/mysql)
normalize Build the normalize modify module (requires dev-libs/libee and dev-libs/liblognorm)
omhttp Build the http output module (requires net-misc/curl)
omhttpfs Build the httpfs output module (requires net-misc/curl)
omudpspoof Build the udpspoof output module (requires net-libs/libnet)
openssl Build the OpenSSL network stream driver (requires dev-libs/openssl)
postgres Build the PostgreSQL database output module (requires dev-db/postgresql)
rabbitmq Build the RabbitMQ output module (requires net-libs/rabbitmq-c)
redis Build the Redis output module using (requires dev-libs/hiredis)
relp Build the Reliable Event Logging Protocol (RELP) output module (requires dev-libs/librelp)
rfc3195 Build the rfc3195 input module (requires dev-libs/liblogging)
rfc5424hmac Build the rfc5424hmac modify module (requires dev-libs/openssl)
snmp Build the snmp modify and output module (requires net-analyzer/net-snmp)
ssl Add support for encrypted client/server communication (requires net-libs/gnutls)
systemd Build the journal input and output module (requires sys-apps/systemd)
usertools Installs the user tools (rsgtutil, rscryutil...) corresponding to the set USE flags
uuid Include UUIDs in messages (requires sys-apps/util-linux)
xxhash Enable xxHash support in fmhash module (requires dev-libs/xxhash)
zeromq Build the ZeroMQ input and output modules (requires net-libs/czmq)

sagan

libdnet Add support for dev-libs/libdnet
pcap Add support for network packet capture via net-libs/libpcap
redis Add support for the Redis database via dev-libs/hiredis
smtp Build witch SMTP (E-Mail) support

salt

cheetah Enable support for dev-python/cheetah3
cherrypy Enable support for using cherrypy.
genshi Enable support for dev-python/genshi
gnupg Enable support for gnupg via python-gnupg.
libcloud Enable salt-cloud support via libcloud.
libvirt Support managing virtual machines with app-emulation/libvirt.
mako Add support for using the mako template engine for parsing salt states.
mongodb Support returning data to a mongodb server.
neutron Support the OpenStack neutron network service.
nova Enable support for the OpenStack Nova API
openssl Add support for using TLS via OpenSSL.
portage Add support for package state enforcement using sys-apps/portage
raet Add support for the new RAET transport.
redis Support returning data to a redis database.
zeromq Add support for the zeromq transport.

sudo

gcrypt Use message digest functions from dev-libs/libgcrypt instead of sudo's
offensive Let sudo print insults when the user types the wrong password
secure-path Replace PATH variable with compile time secure paths
sendmail Allow sudo to send emails with sendmail
sssd Add System Security Services Daemon support

sysklogd

logger Build the logger program
logrotate use app-admin/logrotate for rotating logs rather than custom cron scripts

syslog-ng

amqp Enable support for AMQP destinations
geoip2 Add support for geo lookup based on IPs via dev-libs/libmaxminddb
grpc Enable GRPC based driver support (OpenTelemetry) via net-libs/grpc
http Enable support for HTTP destinations
json Enable support for JSON template formatting via dev-libs/json-c
kafka Enable support for Kafka destinations
mongodb Enable support for mongodb destinations
mqtt Enable MQTT support via net-libs/paho-mqtt-c
pacct Enable support for reading Process Accounting files (EXPERIMENTAL, Linux only)
redis Enable support for Redis destinations
smtp Enable support for SMTP destinations
spoof-source Enable support for spoofed source addresses

sysstat

dcron Adjust cronjobs to work properly under sys-process/dcron

testdisk

ewf Include ewf library
ntfs Include the ability to read NTFS filesystems
reiserfs Include reiserfs reading ability
sudo Enable sudo helper integration

tripwire

ssl Adds support for Secure Socket Layer connections
static Builds the package statically
tools Installs app-admin/mktwpol, providing scripts for the installation/setup of tripwire, including generating the tripwire policy file and maintenance of the tripwire database

ulogd

json Build JSON output plugin to save packets in JSON file format
nfacct Build NFACCT input plugin to support traffic accounting via nfnetlink_acct
nfct Build NFCT input plugin to support stateful flow-based logging via nfnetlink_conntrack
nflog Build NFLOG input plugin to support stateless packet-based logging via nfnetlink_log
pcap Build PCAP output plugin to save packets in libpcap file format
ulog Build ULOG input plugin to support deprecated packet-based logging via ULOG target

vault

webui Enable the Web UI

webalizer

xtended Include the 404 extension

webapp-config

portage Propagate python_targets dependencies to sys-apps/portage

app-alternatives

awk

busybox Symlink to sys-apps/busybox
gawk Symlink to sys-apps/gawk
mawk Symlink to sys-apps/mawk (warning: mawk is not fully POSIX-compliant)
nawk Symlink to sys-apps/nawk

bc

gh Symlink to bc-gh from sci-calculators/bc-gh
gnu Symlink to GNU bc (sys-devel/bc)

bzip2

lbzip2 Symlink to app-arch/lbzip2.
pbzip2 Symlink to app-arch/pbzip2.
reference Symlink to app-arch/bzip2.

cpio

gnu Symlink to GNU cpio (app-arch/cpio)
libarchive Symlink to bsdcpio from app-arch/libarchive

gzip

pigz Symlink to app-arch/pigz.
reference Symlink to app-arch/gzip.

lex

flex Symlink to sys-devel/flex.
reflex Symlink to sys-devel/reflex.

ninja

reference Symlink to dev-build/ninja.
samurai Symlink to dev-build/samurai.

sh

bash Symlink to app-shells/bash
busybox Symlink to sys-apps/busybox
dash Symlink to app-shells/dash
ksh Symlink to app-shells/ksh
lksh Symlink to lksh from app-shells/mksh
mksh Symlink to mksh from app-shells/mksh

tar

gnu Symlink to GNU tar (app-arch/tar)
libarchive Symlink to bsdtar from app-arch/libarchive

yacc

bison Symlink to app-alternatives/yacc.
byacc Symlink to dev-util/byacc.
reference Symlink to dev-util/yacc.

app-antivirus

clamav

clamapp Build applications (clamscan, clamd, clamdscan, clamonacc (also has its own USE flag), sigtool, clambc, clamav-milter (also requires milter USE flag), clamdtop, clamsubmit, clamconf).
clamdtop A Top like tool which shows what clamd is currently scanning amongst other things
clamonacc Build the clamonacc on-access scanner
clamsubmit A tool to submit false positives / negatives
experimental Enable experimental features
libclamav-only Bypass building of libfreshclam and the ClamAV CLI applications.
metadata-analysis-api Enables collection of file property metadata using ClamAV API for analysis by ClamAV bytecode programs.
rar RAR support
system-mspack Use dev-libs/libmspack instead of the version bundled with ClamAV
xml DMG and XAR support

clamtk

kde Install the Dolphin plugin.
nautilus Install the Nautilus plugin.
nemo Install the Nemo plugin.
thunar Install the Thunar plugin.

app-arch

7zip

jwasm Use dev-lang/jwasm to include optimized code (doesn't support AES)
rar Enable support for non-free rar decoder
uasm Use dev-lang/uasm to include optimized code

cabextract

extras Install experimental extra tools: wince_info and wince_rename for examining and processing Windows CE installation cabinet header files; cabinfo for examining the structure of a cab file.

createrepo_c

legacy Build with support for legacy weakdeps and hashes (not recommended!)

dpkg

libmd Use app-crypt/libmd library for message digest functions
update-alternatives Install update-alternatives

dump

ermt encrypted rmt support
uuid Enable UUID support

engrampa

caja Enable engrampa to integrate with mate-base/caja by providing entries in its context menu

file-roller

nautilus Build contextual menu extension for gnome-base/nautilus.

gzip

pic disable optimized assembly code that is not PIC friendly

innoextract

debug Enable debug logging and the --debug command-line option
lzma Enable support for extracting lzma-compressed installers using app-arch/xz-utils

libarchive

blake2 Enable Blake2 hash support via app-crypt/libb2.
bzip2 Allow accessing bzip2-compressed archives through libbz2 (which comes with app-arch/bzip2). This only affects libarchive's native support: bsdtar will keep using bunzip2 as a filter if that's not built-in.
e2fsprogs Use file flags from sys-fs/e2fsprogs headers instead of virtual/os-headers headers
nettle Use dev-libs/nettle as crypto backend

libdeflate

test Build the test programs (requires sys-libs/zlib)
utils Build the libdeflate-gzip program

lrzip-next

largefile Enables support for large files
year2038 Enables support for 64-bit 'time_t' (sets D_TIME_BITS=64; glibc only)

p7zip

natspec Use dev-libs/libnatspec to correctly decode non-ascii file names archived in Windows.
rar Enable support for non-free rar decoder

rar

all-sfx Install all SFX (Self-Extracting) files rather than just the native format (allows creation of Windows EXEs on Linux ELF systems)

rpm

sequoia Use app-crypt/rpm-sequoia instead of the deprecated internal parser

tar

minimal just install `tar`

unzip

natspec Use dev-libs/libnatspec to correctly decode non-ascii file names archived in Windows.

wimlib

fuse Use fuse libraries
iso Install app-cdr/cdrtools in order to prepare iso images
ntfs Use libntfs-3g library from sys-fs/ntfs3g
yasm Use yasm assembler instead of nasm

xz-utils

extra-filters Build additional filters that are not used in any of the default xz presets. This includes delta and BCJ coders, additional match finders and SHA256 checks.
pgo Optimize the build using Profile Guided Optimization (PGO)

zip

natspec Use dev-libs/libnatspec to correctly decode non-ascii file names archived in Windows.

app-backup

amanda

ndmp Support for the NDMP protocol
s3 Support for backing up to the Amazon S3 system
xfs Support for backing up raw XFS filesystems using xfsdump

backup-manager

s3 Support for backing up to the Amazon S3 system

bacula

bacula-clientonly Disable DB support, and just build a client
bacula-nodir Disable building of director
bacula-nosd Disable building of storage daemon
batch-insert Enable batch insert into data base
ipv6 Support IPV6 protocol"
logwatch Install support files for logwatch

bareos

ceph Enable sys-cluster/ceph support
clientonly Only install file-daemon (client)
director Install director
glusterfs Enable sys-cluster/glusterfs storage backend
lmdb enable build of dev-db/lmdb support for faster accurate backup
logwatch Install support files for sys-apps/logwatch
ndmp Enable support for NDMP (Network Data Management Protocol)
scsi-crypto Enable low level SCSI crypto support
storage-daemon Install storage daemon (bareos-sd)
vmware Enable bareos-fd VMware plugin

borgmatic

apprise Allow backup monitoring to send notification to a wide variety of services, using dev-python/apprise

btrbk

lsbtr Enable the lsbtr command-line tool
mbuffer Use sys-block/mbuffer to enable progress bar and buffering/limiting functionality

dar

argon2 Enable password hashing algorithm from app-crypt/argon2
dar32 Enables --enable-mode=32 option, which replace infinite by 32 bit integers
dar64 Enables --enable-mode=64 option, which replace infinite by 64 bit integers
gcrypt Enables strong encryption support
gpg Enables usage of asymmetric encryption algorithms
rsync Enables linking with net-libs/librsync for delta compression support

duplicity

s3 Support for backing up to the Amazon S3 system

rear

udev Have ReaR start backup when attaching your USB drive.

snapper

lvm Enable LVM thinprovisioned snapshots support sys-fs/lvm2
xattr Add support for getting and setting POSIX extended attributes, through sys-apps/attr.

tsm

tsm-cit IBM Tivoli Common Inventory Technology
tsm-hw Difference snapshot support for NetApp and N-Series file servers
vmware Install vmware data protection support

app-benchmarks

filebench

auto-completion Enable command-line autocompletion using dev-libs/libtecla

httperf

idleconn Build with the idleconn program

ioping

netdata Add support for netdata

ramspeed

pic Force shared libraries to be built as PIC (this is slower)

stress-ng

keyutils Stress test the kernel's key generation facilities via sys-apps/keyutils

sysbench

aio Add support for AIO.
attachsql Add support for AttachSQL.
drizzle Add support for Drizzles.
largefile Add support for large files.

app-cdr

brasero

libburn Enable dev-libs/libburn backend
nautilus Build the gnome-base/nautilus extension
playlist Enable support for playlists through dev-libs/totem-pl-parser
tracker Enable audio playlist search using the app-misc/tracker indexer

cdemu

cdemu-daemon Pull app-cdr/cdemu-daemon dependency, useful in chroot environment (bug #315491). Do not disable until you know what you are doing.

dvdisaster

debug Enable memory debugging.

gaffitter

scripts Install additional gaffitter scripts for external programs

mirage2iso

pinentry Support app-crypt/pinentry password input backend.

app-containers

apptainer

network Install network plug-ins
suid Install SUID helper binary

buildah

btrfs Enables dependencies for the "btrfs" graph driver, including necessary kernel flags.

containerd

btrfs Support for BTRFS snapshot driver
cri Support for Kubernetes CRI
device-mapper Support for device mapper snapshot driver

cri-o

btrfs Enables dependencies for the "btrfs" graph driver, including necessary kernel flags.
device-mapper Enables dependencies for the "devicemapper" graph driver, including necessary kernel flags.

crun

bpf Enable in Kernel, eBPF (enhanced Berkley Packet Filter) support for managing device controllers.
criu Enable CRIU based checkpoint/restore support

docker

btrfs Enables dependencies for the "btrfs" graph driver, including necessary kernel flags.
container-init Makes the a staticly-linked init system tini available inside a container.
overlay Enables dependencies for the "overlay" graph driver, including necessary kernel flags.
overlay2 Enables dependencies for the "overlay2" graph driver, including necessary kernel flags.

docker-credential-helpers

pass Build pass helper for the pass utility.

incus

fuidshift Install the fuidshift binary - currently conflicts with app-containers/lxd

lxc

io-uring Enable io_uring support, and use io_uring instead of epoll
tools Build and install additional command line tools

nerdctl

rootless Enables dependencies for running in rootless mode.

podman

btrfs Enables btrfs support (graph driver) in Podman
cgroup-hybrid Use legacy (hybrid) cgroups instead of modern (unified) cgroups
fuse Enables fuse dependencies (fuse-overlayfs is especially useful for rootless mode).
init Enables catatonit dependency required for podman run --init.
rootless Enables dependencies for running in rootless mode.
wrapper Install wrapper which lets use podman for command `docker`

runc

kmem Enable Kernel Memory Accounting.

skopeo

btrfs Enables dependencies for the "btrfs" graph driver.
device-mapper Compiles with libdevmapper
rootless Compiles with libsubid

snapd

forced-devmode Automatically disable application confinement if feature detection fails.

app-crypt

aespipe

cpu_flags_x86_padlock Use VIA padlock instructions, detected at run time, code still works on non-padlock processors

badkeys

dkim Enable dkim scan mode via dev-python/dnspython.
ssh Enable ssh scan mode via dev-python/paramiko.

ccid

twinserial Enable twinserial reader

codecrypt

cryptopp Build algorithms that need Crypto++ support dev-libs/crypto++

dehydrated

cron Install cron job to sign/renew non-existent/changed/expiring certificates

eid-mw

dialogs Enable "askaccess" dialog box, by using x11-libs/gtk+
gtk All dialogs are available, by using x11-libs/gtk+
p11-kit Support for app-crypt/p11-kit.

ekeyd

minimal Only install the ekey-egd-linux service rather than the full ekeyd package.
munin Install a plugin for net-analyzer/munin to graph statistical data from ekeyd.
usb Build the libusb-based userland daemon for accessing the EntropyKey (alternative to the CDC USB driver). It is suggested to use this option by default, as the CDC driver in the kernel often seems to be fragile (or the gadget implementation on the EntropyKey is too buggy), and can cause various problems.

gnupg

smartcard Build scdaemon software. Enables usage of OpenPGP cards. For other type of smartcards, try app-crypt/gnupg-pkcs11-scd. Bring in dev-libs/libusb as a dependency; enable scdaemon.
tofu Enable support for Trust on First use trust model; requires dev-db/sqlite.
tools Install extra tools (including gpgsplit and gpg-zip).
tpm Enable TPM support via app-crypt/tpm2-tss and build tpm2d.
usb Build direct CCID access for scdaemon; requires dev-libs/libusb.
user-socket try a socket directory which is not removed by init manager at session end
wks-server Install the wks-server

gnupg-pkcs11-scd

proxy Build the gnupg-pkcs11-scd-prox

gpgme

common-lisp Install common-lisp files

hashcat

brain Enable the hashcat brain

heimdal

hdb-ldap Adds support for LDAP as a database backend
lmdb Add support for using dev-db/lmdb for lookup tables
otp Adds support for one-time passwords

ima-evm-utils

tpm Enable TPM support

johntheripper-jumbo

opencl Build with opencl/GPU cracking support
pcap Build with pcap support

keybase

fuse Enable app-crypt/kbfs support

kstart

afs Enables afs support which means you can acquire an afs token and set PAGs. It's recommended to set this USE if you need authenticated access to an AFS cell for your daemon/app.

libb2

native-cflags Use CFLAGS as determined by configure script. These flags will enable all CPU specific features it find available, to further optimise the implementation. This discards any existing CFLAGS set in make.conf or similar.

libsecret

tpm Enable Trusted Platform Module support via app-crypt/tpm2-tss

libu2f-host

systemd Use user ACLs rather than plugdev group to give user access to the HIDRAW device.

mit-krb5

doc Creates and installs the API and implementation documentation. This is only useful if you want to develop software which depends on kerberos
keyutils Enable for the keyring ccache using keyutils
lmdb Add support for using dev-db/lmdb for lookup tables
openldap Enable support for ldap as a database backend
pkinit Enable pkinit support for the initial ticket

mkp224o

pcre Search with a regex instead of prefix/suffix matching

onak

dynamic Support for dynamic loading of backends
hkp Proxying backend support

ophcrack

tables Require the additional tables used to carry out cracking (app-crypt/ophcrack-tables)

ophcrack-tables

vistafree Installs the free Vista ophcrack tables
xpfast Installs the fast XP ophcrack tables
xpsmall Installs the small free XP ophcrack tables

pinentry

efl Build dev-libs/efl based pinentry

qca

botan Enable botan plugin
gcrypt Enable gcrypt plugin
gpg Enable GnuPG plugin
logger Enable logger plugin
nss Enable NSS plugin
pkcs11 Enable PKCS#11 plugin
sasl Enable SASL plugin
softstore Enable softstore plugin

rpm-sequoia

nettle Use dev-libs/nettle as a crypto backend
openssl Use dev-libs/openssl as a crypto backend

seahorse

ldap Enable seahorse to manipulate GPG keys on a LDAP server.

swtpm

fuse Support sys-fs/fuse based /dev/tpm interface

tpm-tools

pkcs11 Build Token data management utilities based on OpenCryptoki's (dev-libs/opencryptoki) PKCS#11 implementation.

tpm2-pkcs11

fapi Enable feature API backend

tpm2-tools

fapi Enable feature API tools

tpm2-totp

plymouth Add sys-boot/plymouth support

tpm2-tss

fapi Enable feature API (requires openssl as crypto backend)
mbedtls Use net-libs/mbedtls as crypto engine
openssl Use dev-libs/openssl as crypto engine
policy Enable policy library (requires openssl as crypto backend)

zulucrypt

kwallet Enable encrypted storage of passwords with kde-frameworks/kwallet
udev Whether udev will be consulted when deciding if a volume is system or not

app-dicts

aspell-be

classic Support classic spelling by default

gwaei

hunspell Enable app-text/hunspell spellchecking and morphological analysis
mecab Enable app-text/mecab support

myspell-pt

preao Use the pre ortographic agreement version of the dictionary

app-doc

csound-manual

html Install HTML documentation

devmanual

offline Use alternative minimal stylesheet instead of Tyrian theme

kicad-doc

html Generate documentation in HTML format
pdf Generate documentation in PDF format

linuxfromscratch

htmlsingle Install all-on-one-page HTML version.

pms

html Generate and install PMS as .html as well
twoside Enable two-sided layout suitable for printing

pms-bin

html Install PMS as .html as well

tldp-howto

html Install multi-chapter HTML docs
htmlsingle Install all-on-one-page HTML docs
pdf Install pdf docs
text Install plain-text docs

app-editors

bluefish

gucharmap Enable gucharmap dictionary plugin
spell Enable spell checking capabilities via enchant library

emacs

athena Enable the MIT Athena widget set (x11-libs/libXaw)
dynamic-loading Enable loading of dynamic libraries (modules) at runtime
games Support shared score files for games
gfile Use gfile (dev-libs/glib) for file notification
gmp Use the GNU multiple precision arithmetic library (dev-libs/gmp) instead of the bundled mini-gmp subset
gsettings Use gsettings (dev-libs/glib) to read the system font name
gzip-el Compress bundled Emacs Lisp source
harfbuzz Use media-libs/harfbuzz as text shaping engine
imagemagick Use media-gfx/imagemagick for image processing
jit Compile with Emacs Lisp native compiler support via libgccjit
json Compile with native JSON support using dev-libs/jansson
libxml2 Use dev-libs/libxml2 to parse XML instead of the internal Lisp implementations
mailutils Retrieve e-mail using net-mail/mailutils instead of the internal movemail substitute
source Install C source files and make them available for find-function
threads Add elisp threading support
toolkit-scroll-bars Use the selected toolkit's scrollbars in preference to Emacs' own scrollbars
tree-sitter Support the dev-libs/tree-sitter parsing library
wide-int Prefer wide Emacs integers (typically 62-bit). This option has an effect only on 32-bit systems, where it increases the maximum buffer size from 0.5 to 2 GiB, at the cost of 10% to 30% Lisp slowdown.

fe

sendmail Send mail after editor abend

featherpad

X Link application against X11 libraries which adds support for virtual desktop awareness and tab DND

gedit-plugins

charmap Insert special characters just by clicking on them
git Shows document changes related to git's HEAD
terminal Embed a terminal in the bottom pane

gnome-latex

latexmk Install dev-tex/latexmk (used by default for the build tools)
rubber Install dev-tex/rubber (can be used for the build tools)

gvim

crypt Use dev-libs/libsodium for crypto support
cscope Enable cscope interface
netbeans Include netbeans external editor integration support
racket Enable support for Scheme using dev-scheme/racket

helix

grammar Build and install grammar language files

jasspa-microemacs

nanoemacs Build NanoEmacs instead of MicroEmacs

joe

xterm Enable full xterm clipboard support

leafpad

emacs Enable Emacs key theme

mousepad

shortcuts Build the "shortcuts" plugin

nano

debug Enable debug messages and assert warnings. Note that these will all be sent straight to stderr rather than some logging facility.
justify Enable justify/unjustify functions for text formatting.
magic Add magic file support (sys-apps/file) to automatically detect appropriate syntax highlighting
minimal Disable all fancy features, including ones that otherwise have a dedicated USE flag (such as spelling).

neovim

nvimpager Install nvimpager symlink to less.sh macro

okteta

designer Build plugins for dev-qt/designer

qhexedit2

gui Install Qt5 hex editor

tea

aspell Enable spellchecking using app-text/aspell

vim

X Link console vim against X11 libraries to enable title and clipboard features in xterm
crypt Use dev-libs/libsodium for crypto support
cscope Enable cscope interface
racket Enable support for Scheme using dev-scheme/racket
terminal Enable terminal emulation support
vim-pager Install vimpager and vimmanpager links

vis

tre more memory efficient regex search using dev-libs/tre

vscode

egl Use EGL platform, enables smooth rending in high refresh rate monitors on X11/Xwayland
wayland Run in wayland mode under wayland sessions, xwayland otherwise. This flag doesn't affect x11 sessions.

vscodium

egl Use EGL platform, enables smooth rending in high refresh rate monitors on X11/Xwayland
wayland Run in wayland mode under wayland sessions, xwayland otherwise. This flag doesn't affect x11 sessions.

xemacs

athena Chooses the MIT Athena widget set
bignum Support for OpenSSL bignum implementation
dnd Enables support for the x11-libs/dnd drag-n-drop library
pop Support POP for mail retrieval
xim Enable X11 XiM input method

zed

gles Use simplified OpenGLES instead of full-scale OpenGL

app-emacs

auctex

preview-latex Use bundled preview-latex

bbdb

tex Install plain TeX support files
vm Add support for app-emacs/vm
wanderlust Add support for app-emacs/wanderlust

calfw

howm Add support for the app-emacs/howm note-taking tool

elscreen

wanderlust Include support for app-emacs/wanderlust

emacs-common

games Support shared score files for games
gsettings Install schema file for gsettings (dev-libs/glib)

emacs-w3m

gzip-el Compress bundled Emacs Lisp source

flim

oauth2 Support OAuth2 authentication (app-emacs/oauth2)

gap-mode

completion Install GAP backend for app-emacs/company-mode to "complete anything."
lint Support automatically linting GAP code via app-emacs/flycheck and dev-gap/gaplint.

mu-cite

bbdb Include support for app-emacs/bbdb

org-mode

odt-schema Install non-free schema files for OpenDocument Text exporter

remember

bbdb Include support for app-emacs/bbdb
planner Include support for app-emacs/planner

slime

xref Install xref.lisp cross-referencing tool

sly

xref Install xref.lisp cross-referencing tool

vm

bbdb Include support for app-emacs/bbdb

wanderlust

bbdb Include support for app-emacs/bbdb

wikipedia-mode

outline-magic Enable support for outline-mode extensions (app-emacs/outline-magic)

app-emulation

86Box

experimental Enable hardware from devbranch, which may be unstable or unusable.
fluidsynth Enable MIDI support through media-sound/fluidsynth.
munt Enable MIDI MT-32 support through media-libs/munt-mt32emu.
new-dynarec Enable new dynamic recompiler from PCem 15, which should provide an even better emulation speed.

aranym

clipboard Enable bidirectional clipboard transfer between the host and FreeMiNT
jit Build Just-In-Time compiler variant with increased performance
lilo Enable support for directly booting kernels such as Linux
osmesa Allow images to be rendered in memory using the host CPU
pmmu Build full PMMU variant, required for running mainline Linux
standard Build standard (no JIT or PMMU) variant

bochs

3dnow Enable support for emulating 3DNow! instructions (incomplete)
avx Enable support for emulating Advanced Vector Extensions (AVX)
debugger Enable debugger (slows down emulation)
gdb Enable support for the remote GDB stub
x86-64 Enable support for emulation of 64-bit CPUs

crossover-bin

capi Enable ISDN support via CAPI
osmesa Add support for OpenGL in bitmaps using libOSMesa
pcap Support packet capture software (e.g. wireshark)

dosemu

fluidsynth use media-sound/fluidsynth for MIDI emulation

dxvk

crossdev-mingw Use sys-devel/crossdev for the toolchain rather than dev-util/mingw64-toolchain (requires manual setting up)
d3d10 Enable support for DirectX 10 (d3d10.dll)
d3d11 Enable support for DirectX 11 (d3d11.dll)
d3d8 Enable support for DirectX 8 (d3d8.dll)
d3d9 Enable support for DirectX 9 (d3d9.dll)
dxgi Enable support for the DirectX Graphics Infrastructure (dxgi.dll)

faudio

dumpvoices FAudio dumps buffer data to individual files with RIFF/XWMA headers, usable with players like ffplay/testxwma.

fs-uae

fmv Enable support for CD32 FMV (full motion video)
glew Enable support for The OpenGL Extension Wrangler Library (media-libs/glew)

fs-uae-launcher

lha Enable LHA archive support

fuse

backend-X Use X11 rendering backend
backend-fbcon Use framebuffer rendering backend
backend-gtk3 Use Gtk+ rendering backend
backend-sdl Use SDL rendering backend
backend-svga Use svgalib rendering backend
memlimit Add compile-time memory usage limiting

fuse-utils

gcrypt Use dev-libs/libgcrypt for low-level crypto of some features, including logfiles.

grub-xen-host

pvh Build an additional grub bin for pvh.

hercules-sdl

object-rexx Enable REXX support via Open Object Rexx (dev-lang/oorexx)
regina-rexx Enable REXX support via Regina Rexx (dev-lang/regina-rexx)

libcacard

passthrough Enable smartcard passthrough support via sys-apps/pcsc-lite

libguestfs

erlang Build Erlang bindings
fuse Enable image mount support via sys-fs/fuse
inspect-icons Use media-gfx/icoutils for accessing/inspecting icon file within images
libvirt Use app-emulation/libvirt to manipulate VMs
systemtap Use dev-debug/systemtap to inspect VM via "probes"

libspectrum

gcrypt Use dev-libs/libgcrypt for low-level crypto of some features, including logfiles.

libvirt

dtrace Enable dtrace support via dev-debug/systemtap
firewalld DBus interface to iptables/ebtables allowing for better runtime management of your firewall.
fuse Allow LXC to use sys-fs/fuse for mountpoints
glusterfs Enable GlusterFS support via sys-cluster/glusterfs
iscsi Allow using an iSCSI remote storage server as pool for disk image storage
iscsi-direct Allow using libiscsi for iSCSI storage pool backend
libssh Use net-libs/libssh to communicate with remote libvirtd hosts, for example: qemu+libssh://server/system
libssh2 Use net-libs/libssh2 to communicate with remote libvirtd hosts, for example: qemu+libssh2://server/system
libvirtd Builds the libvirtd daemon as well as the client utilities instead of just the client utilities
lvm Allow using the Logical Volume Manager (sys-fs/lvm2) as pool for disk image storage
lxc Support management of Linux Containers virtualisation (app-containers/lxc)
nbd Allow using sys-block/nbdkit to access network disks
nfs Allow using Network File System mounts as pool for disk image storage
numa Use NUMA for memory segmenting via sys-process/numactl and sys-process/numad
openvz Support management of OpenVZ virtualisation (openvz-sources)
parted Allow using real disk partitions as pool for disk image storage, using sys-block/parted to create, resize and delete them.
pcap Support auto learning IP addreses for routing
qemu Support management of QEMU virtualisation (app-emulation/qemu)
rbd Enable rados block device support via sys-cluster/ceph
virt-network Enable virtual networking (NAT) support for guests. Includes all the dependencies for NATed network mode. Effectively any network setup that relies on libvirt to setup and configure network interfaces on your host. This can include bridged and routed networks ONLY if you are allowing libvirt to create and manage the underlying devices for you. In some cases this requires enabling the 'netcf' USE flag (currently unavailable).
virtiofsd Drag in virtiofsd dependency app-emulation/virtiofsd
virtualbox Support management of VirtualBox virtualisation (app-emulation/virtualbox)
wireshark-plugins Build the net-analyzer/wireshark plugin for the Libvirt RPC protocol
xen Support management of Xen virtualisation (app-emulation/xen)
zfs Enable ZFS backend storage sys-fs/zfs

nemu

network-map Adds possibility of exporting network map to SVG
ovf Adds support for OVA/OVF import
remote-api Adds API for remote control
spice Adds Spice protocol support
vnc-client Adds support for external VNC client

open-vm-tools

deploypkg Build deploypkg plugin
dnet Enable support for nicinfo
doc Generate API documentation
fuse Enable vmblock-fuse/vmhgfs-fuse
gtkmm Compile with Gtkmm and sigc++ (Recommended)
multimon Enable multimon (Requires X)
resolutionkms Build the linux/unix resolutionkms module
vgauth Build vgauth

pcem

networking Enable support for emulation of network cards.

punes

cg Add support for Nvidia CG Toolkit

q4wine

ico Enable ico support via media-gfx/icoutils
iso Support unprivileged mounting of ISO9660 images via sys-fs/fuseiso
wineappdb Enable Wine AppDB browser support

qemu

accessibility Adds support for braille displays using brltty
aio Enables support for Linux's Async IO
alsa Enable alsa output for sound emulation
bpf Enable eBPF support for RSS implementation.
capstone Enable disassembly support with dev-libs/capstone
curl Support ISOs / -cdrom directives via HTTP or HTTPS.
fdt Enables firmware device tree support
fuse Enables FUSE block device export
glusterfs Enables GlusterFS cluster fileystem via sys-cluster/glusterfs
gnutls Enable TLS support for the VNC console server. For 1.4 and newer this also enables WebSocket support. For 2.0 through 2.3 also enables disk quorum support.
io-uring Enable efficient I/O via sys-libs/liburing.
iscsi Enable direct iSCSI support via net-libs/libiscsi instead of indirectly via the Linux block layer that sys-block/open-iscsi does.
jemalloc Enable jemalloc allocator support
jpeg Enable jpeg image support for the VNC console server
keyutils Support Linux keyrings via sys-apps/keyutils
multipath Enable multipath persistent reservation passthrough via sys-fs/multipath-tools.
ncurses Enable the ncurses-based console
nfs Enable NFS support
numa Enable NUMA support
pin-upstream-blobs Pin the versions of BIOS firmware to the version included in the upstream release. This is needed to sanely support migration/suspend/resume/snapshotting/etc... of instances. When the blobs are different, random corruption/bugs/crashes/etc... may be observed.
pipewire Enable pipewire output for sound emulation
plugins Enable qemu plugin API via shared library loading.
png Enable png image support for the VNC console server
pulseaudio Enable pulseaudio output for sound emulation
rbd Enable rados block device backend support, see https://docs.ceph.com/en/mimic/rbd/qemu-rbd/
sdl Enable the SDL-based console
sdl-image SDL Image support for icons
slirp Enable TCP/IP in hypervisor via net-libs/libslirp
spice Enable Spice protocol support via app-emulation/spice
ssh Enable SSH based block device support via net-libs/libssh2
static Build the User and Software MMU (system) targets as well as tools as static binaries
static-user Build the User targets as static binaries
systemtap Enable SystemTap/DTrace tracing
usb Enable USB passthrough via dev-libs/libusb
usbredir Use sys-apps/usbredir to redirect USB devices to another machine over TCP
vde Enable VDE-based networking
vhost-net Enable accelerated networking using vhost-net, see https://www.linux-kvm.org/page/VhostNet
virgl Enable experimental Virgil 3d (virtual software GPU)
virtfs Enable VirtFS via virtio-9p-pci / fsdev. See https://wiki.qemu.org/Documentation/9psetup
vte Enable terminal support (x11-libs/vte) in the GTK+ interface
xattr Add support for getting and setting POSIX extended attributes, through sys-apps/attr. Requisite for the virtfs backend.
xdp Enable support for XDP through net-libs/xdp-tools
xen Enables support for Xen backends

ski

debug enable extra binary emulation debugging via sys-libs/binutils-libs

spice

smartcard Enable smartcard remoting using app-emulation/libcacard

uade

fuse Enable sys-fs/fuse uadefs frontend for on-the-fly WAV conversion

vice

ethernet Enable ethernet emulation
headless Include the headless variant of the emulator
mpg123 Enable mp3@64 cartridge support
parport Enable parallel port SID support
pci Enable PCI device discovery using sys-apps/pciutils

virt-manager

policykit Enables sys-auth/polkit authentication support, required when using app-emulation/libvirt with PolicyKit authentication
sasl Depend on the proper libraries needed to connect to SASL-enabled libvirtd instances (e.g. Kerberos-protected instances).

virt-viewer

libvirt Support connecting to virtual machines managed by libvirt.
spice Support connecting to SPICE-enabled virtual machines.
vnc Support connecting to VNC-enabled virtual machines.
vte Enable terminal support (x11-libs/vte) in the GTK+ interface

virt-what

dmi Use sys-apps/dmidecode to read firmware data

virtualbox

dtrace Install dtrace Extension Pack.
headless Build without any graphic frontend.
lvm Build VBoxVolInfo that needs devicemapper from sys-fs/lvm2.
pax-kernel Apply patch needed for pax enabled kernels.
sdk Enable building of SDK.
udev Controls installation of special USB udev rules.
vboxwebsrv Build and install the VirtualBox webservice.
vde Support for VDE networking via net-misc/vde.
vmmraw Enable 32-bit support on a 64-bit kernel.

virtualbox-kvm

dtrace Install dtrace Extension Pack
hardened Enable hardening and install binaries SUID
lvm Build VBoxVolInfo that needs devicemapper from sys-fs/lvm2.
sdk Enable building of SDK
udev Controls installation of special USB udev rules.
vboxwebsrv Build and install the VirtualBox webservice
vde Support for VDE networking via net-misc/vde
vmmraw Enable 32-bit support on a 64-bit kernel.

vkd3d

spirv-tools Enable SPIRV shader debugging support using dev-util/spirv-tools

vkd3d-proton

crossdev-mingw Use sys-devel/crossdev for the toolchain rather than dev-util/mingw64-toolchain (requires manual setting up)
extras Install extra tools and demos in /usr/lib/vkd3d-proton

wine-gecko

shared Install pre-unpacked files which do not need to be copied into the Wine prefix

wine-mono

shared Install pre-unpacked files which do not need to be copied into the Wine prefix (note that this requires the default top-level Z: drive to be kept for out-of-prefix files to be readable)

wine-proton

crossdev-mingw Use sys-devel/crossdev for the toolchain rather than dev-util/mingw64-toolchain (requires manual setting up)
gecko Enable mshtml support using app-emulation/wine-gecko
mono Enable .NET support using app-emulation/wine-mono
osmesa Enable off-screen rendering (OpenGL in bitmaps) support
perl Install helpers that require perl (winedump/winemaker)
sdl Enable gamepad support using media-libs/libsdl2
vkd3d Enable DirectX 12 support using app-emulation/vkd3d
wow64 Enable running 32bit applications without 32bit ELF multilib by mapping to 64bit calls (experimental, *may* have worse/unusable OpenGL performance or other issues compared to USE=abi_x86_32, also lacks 16bit support) -- still need dev-util/mingw64-toolchain with abi_x86_32 which itself does not need multilib

wine-staging

capi Enable ISDN support using net-libs/libcapi
crossdev-mingw Use sys-devel/crossdev for the toolchain rather than dev-util/mingw64-toolchain (requires manual setting up)
dos Pull in games-emulation/dosbox to run DOS applications
gecko Enable mshtml support using app-emulation/wine-gecko
mingw Build PE files using a MinGW toolchain for better compatibility
mono Enable .NET support using app-emulation/wine-mono
netapi Enable support for configuring remote shares using net-fs/samba
osmesa Enable off-screen rendering (OpenGL in bitmaps) support
pcap Support packet capture software (e.g. wireshark)
perl Install helpers that require perl (winedump/winemaker)
samba Pull in net-fs/samba with winbind for NTLM auth support
sdl Enable gamepad support using media-libs/libsdl2
wow64 Enable running 32bit applications without 32bit ELF multilib by mapping to 64bit calls (experimental, *may* have worse/unusable OpenGL performance or other issues compared to USE=abi_x86_32, also lacks 16bit support) -- still need dev-util/mingw64-toolchain with abi_x86_32 which itself does not need multilib

wine-vanilla

capi Enable ISDN support using net-libs/libcapi
crossdev-mingw Use sys-devel/crossdev for the toolchain rather than dev-util/mingw64-toolchain (requires manual setting up)
dos Pull in games-emulation/dosbox to run DOS applications
gecko Enable mshtml support using app-emulation/wine-gecko
mingw Build PE files using a MinGW toolchain for better compatibility
mono Enable .NET support using app-emulation/wine-mono
netapi Enable support for configuring remote shares using net-fs/samba
osmesa Enable off-screen rendering (OpenGL in bitmaps) support
pcap Support packet capture software (e.g. wireshark)
perl Install helpers that require perl (winedump/winemaker)
samba Pull in net-fs/samba with winbind for NTLM auth support
sdl Enable gamepad support using media-libs/libsdl2
vkd3d Enable DirectX 12 support using app-emulation/vkd3d
wow64 Enable running 32bit applications without 32bit ELF multilib by mapping to 64bit calls (experimental, *may* have worse/unusable OpenGL performance or other issues compared to USE=abi_x86_32, also lacks 16bit support) -- still need dev-util/mingw64-toolchain with abi_x86_32 which itself does not need multilib

winetricks

rar Pull in app-arch/unrar for extraction of rar-compressed game files

x48

readline Enables support for libreadline

xe-guest-utilities

xenstore Use xenstore binaries bundled by Citrix instead of building app-emulation/xen-tools

xen

boot-symlinks Symlink xen.gz variants in /boot, disable on fat filesystems
flask Enable the Flask XSM module from NSA
uefi Adds UEFI boot support, requires LDFLAG -melf_x86_64 for amd64

xen-tools

api Build the C libxenapi bindings
hvm Enable support for hardware based virtualization (VT-x,AMD-v)
ipxe Enable ipxe support
ovmf Enable support to boot UEFI guest vm, needed by hvm
pygrub Install the pygrub boot loader
qemu Enable IOEMU support via the use of qemu-dm
qemu-traditional Build the old qemu traditional device model (useful only if you cannot change to the new device model e.g. Windows VMs)
rombios Enable rombios support, needed by ipxe
screen Enable support for running domain U console in an app-misc/screen session
system-ipxe Using sys-firmware/ipxe instead of the bundled one
system-qemu Using app-emulation/qemu instead of the bundled one
system-seabios Using sys-firmware/seabios instead of the bundled one

xtrs

ls-dos Install LS-DOS disk images for Model 4P

app-eselect

eselect-php

fpm Enable the FastCGI Process Manager SAPI

eselect-wine

xdg Set XDG_DATA_DIRS to use the selected wine.desktop, allows e.g. 'xdg-open my.exe' for file managers

app-forensics

afflib

fuse Enable extra fuse thingies
qemu Enable qemu stuff
s3 Enable support for Amazon S3

aide

curl Use curl for http,https and ftp backends
e2fs Enable support for checking file attributes on ext2/ext3/ext4 filesystems

chkrootkit

cron Install cron script for weekly rootkit scans

honggfuzz

clang Enable clang support (pull sys-libs/blocksruntime dependency).

lynis

cron Install /etc/cron.* files

sleuthkit

aff Enable extra aff formats
ewf Enable libewf support

volatility3

crypt support plugins that decrypt passwords, password hashes, etc.
disasm support plugins that perform malware analysis and disassemble code
jsonschema improve error messages regarding improperly configured ISF files
leechcore support memory acquisition via leechcore
snappy support AVMLs native compression format
yara support YARA pattern matching engine

yara

cuckoo Enable cockoo module
dex Enable dex module
dotnet Enable dotnet module
macho Enable macho module
magic Enable magic module
profiling Enable rules profiling
python Pulls in python binding via dev-python/yara-python

app-i18n

fcitx

autostart Enable XDG-compatible autostart of Fcitx
emoji Enable emoji loading for CLDR
enchant Enable Enchant backend (using app-text/enchant) for spelling hinting
gtk2 Install input method module for GTK+ 2
gtk3 Install input method module for GTK+ 3
keyboard Enable key event translation with XKB and build keyboard engine
opencc Enable OpenCC engine (using app-i18n/opencc) for converter between Simplified Chinese and Traditional Chinese
pango Enable support for x11-libs/pango
presage Enable presage for word predication (not stable)
server Build a fcitx as server, disable this option if you want to use fcitx as an embedded library
table Install table input methods for Simplified Chinese
xkb Enable support for XKB (required for fcitx-xkb, fcitx-xkbdbus, part of fcitx-keyboard)

fcitx-chinese-addons

cloudpinyin Build cloud pinyin addon
data Build data
gui Enable GUI support (qt5 or qt6)
opencc Enable support for conversion between Traditional and Simplified Chinese
qt5 Enable configure qt5
webengine Enable built-in browser using dev-qt/qtwebengine

fcitx-configtool

config-qt Enable fcitx5-config-qt
kcm Enable KDE KCM support
test Enable Test

fcitx-gtk

gtk2 Install input method module for GTK+ 2
gtk3 Enable support for GTK+3
gtk4 Enable support for GTK 4
onlyplugin Build only plugin
snooper Enable key snooper for gtk app

fcitx-libpinyin

dictionary-manager Install dictionary manager

fcitx-lua

dlopen Use dlopen to load lua library

fcitx-qt

onlyplugin Build only plugin
qt6 Build support for QT6
staticplugin Build plugin as static

fcitx-rime

configuration-tool Install configuration tool

fcitx-unikey

macro-editor Install macro editor

ibus

emoji Enable support for Emoji
gtk2 Enable the GTK-2 input method module
gtk3 Enable the GTK-3 input method module
gtk4 Enable the GTK-4 input method module
unicode Enable support for Unicode choice

ibus-handwrite

zinnia Enable support for app-i18n/zinnia

ibus-libpinyin

boost Compile against dev-libs/boost libraries
opencc Enable support for app-i18n/opencc

ibus-pinyin

boost Enable support for dev-libs/boost

im-chooser

xfce Enable support for XFCE panel

imsettings

xfconf Enable support for xfce-base/xfconf

libime

data Build data

librime

debug Enable debugging (including logging of input of RIME input methods)

mozc

fcitx4 Enable support for app-i18n/fcitx 4
fcitx5 Enable support for app-i18n/fcitx 5
gui Install graphical user interface tool (mozc_tool)
ibus Enable support for app-i18n/ibus
renderer Enable native candidate window

pyzy

boost Enable support for dev-libs/boost
doc Generate API documentation
opencc Enable support for app-i18n/opencc

rime-data

extra Install extra packages

scim

gtk3 Enable support for x11-libs/gtk+:3

scim-anthy

gtk3 Enable support for x11-libs/gtk+:3
kasumi Use Anthy dictionary maintenance tool (app-dicts/kasumi)

tomoe

hyperestraier Enable support for app-text/hyperestraier

uim

anthy Enable support for app-i18n/anthy
eb Enable support for dev-libs/eb
gtk2 Enable support for x11-libs/gtk+:2
skk Enable support for app-i18n/skk-jisyo

app-laptop

hdapsd

libconfig Require dev-libs/libconfig to allow the daemon to read a configuration file at startup

ibam

gkrellm Enable building of app-admin/gkrellm module

laptop-mode-tools

apm Add APM (Advanced Power Management) support

pbbuttonsd

ibam Enable support for Intelligent Battery Monitoring
macbook Enable support for the Macbook and Macbook Pro

thinkfan

atasmart include libatasmart support to get disc temperature
nvidia allow thinkfan to read GPU temperature from the proprietary nVidia driver
yaml use YAML format for config file

tp_smapi

hdaps Install a compatible HDAPS module

app-metrics

collectd

contrib Install user-contributed files in the doc directory
filecaps When set collectd daemon will have set required capabilities to run most plugins even if run as unprivileged user
java Must be set (workaround for java-pkg-opt-2 eclass limitation) when you want java or genericjmx plugin
udev Enable optional udev usage in disk plugin; Required for smart plugin
xfs Enable optional capability to filter on XFS file system in df plugin; Requires XFS headers from sys-fs/xfsprogs

node_exporter

systemd Enables systemd collector by default

prometheus-podman-exporter

btrfs Collect metrics for btrfs filesystem

app-misc

FreeSSM

small-resolution Build the app for small resolution screeens

anki

gui Enable support for a graphical user interface. Disable for standalone sync server.

blink1

mini-tool Build and install command-line mini-tool blink1-mini-tool (normally used for embedded devices)
server Build and install REST API server (currently hard-coded to TCP port 8080)
tool Build and install command-line tool blink1-tool

broot

X X11 clipboard interaction

byobu

screen Use app-misc/screen as the default backend

ca-certificates

cacert Include root/class3 certs from CAcert (https://www.cacert.org/)

carbon-c-relay

client build and install sendmetric client utility
lz4 add support for LZ4 compressed transport
oniguruma use dev-libs/oniguruma as regex implementation
pcre2 use dev-libs/libpcre2 as regex implementation
snappy add support for Snappy compressed transport

ddccontrol

pci enable direct PCI memory access (the setuid ddcpci util)

ddcutil

drm Use x11-libs/libdrm for more verbose diagnostics.
usb-monitor Adds support for monitors attached via USB.
user-permissions Adds a udev rules to allow non-root users in the i2c group to access the /dev/i2c-* devices. If usb-monitor is selected, users will need to be added to the video group to access the USB monitor. Otherwise, only root will be able to use ddcutil.

digitemp

ds2490 Build support for the ds2490 sensor
ds9097 Build support for the ds9097 sensor
ds9097u Build support for the ds9097u sensor

ebusd

contrib Compile and install additional user contribued plugins.
knx Enable support for connecting to KNX.
mqtt Enable support for connecting to MQTT.

fastfetch

chafa Enables text/graphics renderer with media-gfx/chafa
ddcutil Use app-misc/ddcutil to query monitor settings
drm Enables support for X.org's x11-libs/libdrm
elf Use libelf to extract strings from binaries
osmesa Enables offscreen rendering support from media-libs/mesa
vulkan Enables reading GPU via media-libs/vulkan-loader
xfce Enables support for XFCE config
xrandr Enables support for Xrandr

g810-led

hidapi Use dev-libs/hidapi instead of virtual/libusb for talking to the device (advertised to be faster)

geoclue

modemmanager Enable geolocation through 3G or GPS enabled hardware through net-misc/modemmanager.
zeroconf Enable retrieval of GPS location from Android devices with https://wiki.gnome.org/Apps/GeoclueShare

gramps

geo Enable rendering of geographical data using sci-geosciences/osm-gps-map
rcs Adds support for family tree archives via dev-vcs/rcs
reports All external software that is needed for graphical reports will be installed

graphlcd-base

fontconfig Add support for media-libs/fontconfig font names.
freetype Add support for media-libs/freetype.
graphicsmagick Add support for media-gfx/graphicsmagick.
imagemagick Add support for media-gfx/imagemagick.

irtrans-irserver

mono Enable mono support

jdupes

dedupe Enable deduplication support

jp

jpp Install jpp which is an extended superset of the jp CLI for JMESPath

jpipe

jp-symlink Install a jp symlink that points to jpipe.
jpp-symlink Install a jpp symlink that points to jpipe.

jq

oniguruma Use dev-libs/oniguruma for regular expression support

kryoflux-dtc

demos Install example floppy game files.
fast-firmware Install fast firmware instead of slow firmware.

lcd4linux

apm Enable the APM plugin.
asterisk Enable the Asterisk plugin.
button-exec Enable the Button plugin, to execute something on keypress.
cpuinfo Enable the cpuinfo plugin.
dbus Enable the dbus plugin.
diskstats Enable the diskstats plugin.
dvb Enable support for the DVB plugin.
event Enable the event plugin.
exec Enable the exec plugin, to read output from external programs.
fifo Enable the FIFO (First-In, First-Out) plugin.
file Enable the file plugin, to read from input from files.
gps Enable the gps plugin, for reading gps coordinates.
hddtemp Enable the hddtemp plugin, to read from the hddtemp daemon.
huawei Enable the huawei plugin, to read from a huawei device.
i2c-sensors Enable the i2c_sensors plugin, to read sensor data.
iconv Enable the iconv plugin, to convert between encodings.
isdn Enable the isdn plugin, to get information about ISDN.
kvv Enable the kvv plugin, to get realtime train schedule from the Karlsruher Verkehrsverbund.
loadavg Enable the loadavg plugin, to get stats load
meminfo Enable the meminfo plugin, to get memory statistics.
mpd Enable the mpd plugin, to read from the Music Player Daemon.
mpris-dbus Enable the mpris plugin, to read data via dbus for mpris.
mysql Enable the mysql plugin, to get mysql database information.
netdev Enable the netdev plugin, to get interface statistics.
netinfo Enable the netinfo plugin, to get more interface statistic.
outb Enable raw i/o access.
pop3 Enable the pop3 plugin, to get notified about new mails.
proc-stat Enable the proc_stat plugin, to read data from the proc file system.
python Enable support for dev-lang/python and enable the python plugin, to execute own python scripts.
qnaplog Enable the qnaplog plugin, to read a log from a QNAP device.
raspi Enable the raspi plugin, to read sensor data from a Raspberry Pi.
sample Enable the sample plugin.
statfs Enable the statfs plugin, to get statistics about the file system.
uname Enable the uname plugin, to get the output of uname.
uptime Enable the uptime plugin.
w1retap Enable the w1retap plugin.
wireless Enable the wireless plugin, to get wireless statistics.

lcdproc

ethlcd Enable support for ethlcd in the hd44780 driver.
extra-charmaps Enable extra language specific charmaps.
menu Enable menu support in the lcdproc client.
nfs Display NFS filesystem stats in the lcdproc client.
png Enable support for media-libs/libpng in the glcd driver.
samba Display SMBFS filesystem stats in the lcdproc client.
test-menu Enable test menu support for the lcdproc server.
truetype Enable support for media-libs/freetype in the glcd driver.

libdatovka

openssl Use openssl backend

lirc

audio Support using an audio device connected to an IR receiver
devinput Support the devinput input device
ftdi Support FTDI devices
gtk Include GTK support which enables the use of lirc-setup
inputlirc Add a dependency on app-misc/inputlircd
uinput Enable support for uinput

mc

edit Compile and install the mcedit application
sftp Add support for sftp (uses net-libs/libssh2 for it).
slang Use sys-libs/slang instead of sys-libs/ncurses.

mime-types

nginx Enable mime-types support for www-servers/nginx package

mosquitto

bridge Enable bridge support in the MQTT broker.
persistence Store messages and subscriptions to a file.
srv Include SRV lookup support.
websockets Support the WebSocket protocol.

muttprint

doc Builds documentation

neofetch

X Enable support for detecting DEs, WMs, screen resolutions, and showing images from an X terminal

nnn

8contexts Enable 8 contexts (instead of 4)
colemak Key bindings for Colemak keyboard layout
emoji Display icons using emoji
gitstatus Add git status column to the detail view
icons Display icons using icons-in-terminal
namefirst Print filenames first in the detail view
nerdfonts Display icons using nerdfonts icons
qsort Use Alexey Tourbin's quick sort implementation
restorepreview Add pipe to close and restore preview-tui for internal undetached edits

note

general Add support for ascii flatfile backend
text Add support for text backend

ola

ftdi Support FTDI devices
http Enable built-in Web UI
rdm-tests Install RDM responder tests

pax-utils

python Install a more powerful/faster version of lddtree

recoll

camelcase Enable indexing for camelCase sentences and words
chm Enable CHM file support via dev-python/pychm
inotify Use the Linux Kernel notification subsystem for monitoring file alterations in realtime
session Stop monitoring file alterations when X11 session terminates
webengine Use dev-qt/qtwebengine for fancy result list display

rlwrap

debug Enable debug

screen

multiuser Enable multiuser support (by setting correct permissions)
nethack Express error messages in nethack style

screenfetch

X Use the media-gfx/scrot package to take screenshots

sphinx

id64 use 64-bit document and word IDs
mariadb Add mariadb database support
stemmer Enable language stemming support

task

sync Enable "task sync" support

tmux

utempter Include libutempter support

tracker

miners Install the app-misc/tracker-miners package for actual data mining support for tracker
stemmer Add word stemming via dev-libs/snowball-stemmer.

tracker-miners

cue Enable cue sheet parsing
gsf Enable gnome-extra/libgsf based data extractor and for ODT.
iptc Enable extraction of IPTC data from pictures
iso Enable extraction of metadata from ISO disk images
playlist Add support for playlists
xps Add support for XPS file format through app-text/libgxps.

unfoo

minimal Do not install all support archive binaries

vcontrold

vclient Build the vclient helper program to talk to vcontrold
vsim Build the vsim helper program (simulates the heating's answers, for development and debugging)

vifm

extended-keys Support for extended keys (arrows, home etc)
gtk Use gtk+ to determine mimetypes
vim Install the vifm vim plugin and vim-compatible documentation

worker

avfs Enable support for sys-fs/avfs

yq

yq-symlink Create a yq symlink to yq-python.

yq-go

yq-symlink Create a yq symlink to yq-go.

app-mobilephone

gammu

curl Enables curl support
irda Enables infrared support
mysql Use mysql for data storage
nls Enable native language support
odbc Use ODBC as DB connector
postgres Use PostgreSQL for data storage
usb Enable USB suport

gnokii

ical Enable support for dev-libs/libical
irda Enable infrared support
pcsc-lite Enable smartcard support with sys-apps/pcsc-lite
sms Enable SMS support (build smsd)

smstools

stats Enable statistic reporting

app-office

abiword

collab Enable collaborative editing plugin
goffice Enable goffice plugin
grammar Enable grammar checking via dev-libs/link-grammar
map Enable world map support through media-libs/libchamplain
math Enable support for x11-libs/gtkmathview
ots Enable Text Summarizer plugin
plugins Enable plugins build (see http://www.abisource.com/wiki/PluginMatrix for more information). If your file cannot be opened due lack of support, try enabling this.
redland Enables support redland and raptor libs.
thesaurus Enable thesaurus support
wordperfect Enable wordperfect file support via app-text/libwpd

calcurse

caldav Support CalDAV

calligra

charts Build chartshape plugin for creating business charts with dev-libs/kdiagram
import-filter Enable support for various import filter file formats like WordPerfect, Visio and Apple Keynote
lcms Build colorengine plugins using media-libs/lcms
okular Enable bindings for kde-apps/okular
phonon Build stage/eventplugins and videoshape plugin using media-libs/phonon
webengine Enable Braindump support using dev-qt/qtwebengine

calligraplan

activities Enable kactivities support
holidays Enable kde-frameworks/kholidays integration
kwallet Enable access to encrypted OpenDocument files with kde-frameworks/kwallet storage

glabels

barcode Enable barcode support through external libraries.

gnucash

aqbanking Connect to some internet banks via AqBanking
quotes Enable online stock quote retrieval

gnumeric

libgda Enable database support through gnome-extra/libgda.
perl Enable perl plugin loader.

grisbi

goffice enable goffice graphic support

kmymoney

activities Enable kde-plasma/plasma-activities integration
addressbook Enable kde-apps/akonadi contact integration
hbci Enable HBCI support using net-libs/aqbanking
holidays Enable kde-frameworks/kholidays integration

kraft

pim Enable support for KDE PIM resources integration

libalkimia

webengine Enable online quotes using dev-qt/qtwebengine

libreoffice

base Enable full support for LibreOffice Base databases (involves additional bundled libs)
clang Use Clang compiler instead of GCC
coinmp Use sci-libs/coinor-mp as alternative solver
googledrive Enable support for remote files on Google Drive
mariadb Prefer mariadb connector over mysql connector
odk Build the Office Development Kit
pdfimport Enable PDF import via the Poppler library
vulkan Enable Vulkan usage via the skia library (clang recommended)

libreoffice-l10n

offlinehelp Install help files locally instead of using the LibreOffice Wiki

lyx

aspell Add support for aspell spellchecking
dia Add support for diagrams (app-office/dia)
dot Add support for DOT import (media-gfx/graphviz)
enchant Add support for enchant spellchecking wrapper (both aspell and hunspell can be used by LyX).
gnumeric Add support for importing Gnumeric/OpenOffice/MS Excel spreadsheets into LyX.
html Add support for HTML import
hunspell Add support for spellchecking based on hunspell and reuse system-wide OpenOffice dictionaries. This also enable thesaurus dictionaries not accessible via aspell.
monolithic-build This should speed up compilation significantly when you have enough RAM (> 600 MB)
rcs Add support for revision control via dev-vcs/rcs
rtf Add support for RTF import/export packages

magicpoint

contrib Install additional contributed scripts

mdbtools

glib Use functions provided by dev-libs/glib, not built-in

planner

libgda PostgreSQL support via gnome-extra/libgda

sc-im

X Use x11-misc/xclip for clipboard copy/paste
ods Add ods import support
plots Add sci-visualization/gnuplot for plotting support
tmux Use app-misc/tmux for clipboard copy/paste
wayland Use gui-apps/wl-clipboard for clipboard copy/paste
xls Add xls support
xlsx Add xlsx support

scribus

boost Enable support for Boost based enhancement
hunspell Enable support for spell checking with app-text/hunspell
minimal Don't install headers (only required for e.g. plug-in developers)
osg 3D rendering via dev-games/openscenegraph
scripts Install the scripts
templates Document templates
tk Install tk based scripts e.g. FontSample.py

skrooge

activities Enable kactivities support

texmacs

netpbm Add support for media-libs/netpbm

texstudio

video Enable video player in pdf files

app-pda

gtkpod

clutter Enable clutter support for displaying coverart

app-portage

conf-update

colordiff Use colors when displaying diffs (app-misc/colordiff)

eix

debug Build with upstream's CXXFLAGS/LDFLAGS for debugging support; not recommended for normal use.
doc Create description of the eix cache file additionally in html format
sqlite Compile in support for portage's sqlite backend; to actually use it you need additional configuration of portage and eix

gemato

gpg Install dependencies needed for OpenPGP signature verification support
pretty-log Pull dev-python/rich to enable pretty logs
tools Install additional utilities (benchmarks, hash testing tools, fast Manifest generators) to /usr/share/gemato.

grs

server Install all the tools building systems

hackport

profile Enable profiling flags

kuroneko

scraper Include the dependencies necessary for Bugzilla scraping.

nattka

depgraph-order Process packages in depgraph order whenever possible.

pfl

network-cron Adds a cron job which does a weekly submit of the package database

portage-utils

qmanifest Build qmanifest applet, this adds additional dependencies for GPG, OpenSSL and BLAKE2B hashing
qtegrity Build qtegrity applet, this adds additional dependencies for OpenSSL

tatt

templates Install template scripts to be used with tatt

app-shells

atuin

client Enable the autin client
daemon Enable the autin background daemon on the client
server Enable the autin server
sync Enable the server-sync feature in the autin client

autojump

ipython Add support for dev-python/ipython

bash

bashlogger Log ALL commands typed into bash; should ONLY be used in restricted environments such as honeypots
mem-scramble Build with custom malloc/free overwriting allocated/freed memory
net Enable /dev/tcp/host/port redirection
pgo Optimize the build using Profile Guided Optimization (PGO)
plugins Add support for loading builtins at runtime via 'enable'

bash-completion

eselect Support blacklisting of completions via 'eselect bashcomp'. This enables custom Gentoo patching of upstream completion loader.

mksh

lksh variant that uses POSIX-compliant arithmetics with the host “long” data type and is automatically in POSIX mode when called as /bin/sh

nushell

plugins Build official plugins

pdsh

rsh This allows the use of rsh (remote shell) and rcp (remote copy) for authoring websites. sftp is a much more secure protocol and is preferred.

shish

diet Use dev-libs/dietlibc

app-text

atril

caja Enable property page extension in mate-base/caja
dvi Enable build-in DVI viewer
epub Enable build-in DVI viewer using net-libs/webkit-gtk
synctex Enable search highlighting through synctex (virtual/tex-base)
t1lib Enable the Type-1 fonts for the build-in DVI viewer (media-libs/t1lib)
xps Enable XPS viewer using app-text/libgxps

blogc

git Build blogc-git-receiver tool
httpd Build blogc-runserver tool
make Build blogc-make tool

calibre

font-subsetting Enable font subsetting support
system-mathjax Use a system copy of mathjax
unrar Enable support for comic books compressed with the non-free Rar format

cmigemo

vim Install Vim plugin for C/Migemo

crengine-ng

chm Support chm format
fribidi Support bidirectional text by dev-libs/fribidi
harfbuzz Use media-libs/harfbuzz for kerning and ligatures
libunibreak Use dev-libs/libunibreak for hyphenation
libutf8proc Use dev-libs/libutf8proc for manipulating unicode strings

crm114

mew Add support for using the mewdecode mime decoder (app-emacs/mew)
normalizemime Add support for using the normalizemime (mail-filter/normalizemime)

crqt-ng

chm Support chm format
fribidi Support bidirectional text by dev-libs/fribidi
harfbuzz Use media-libs/harfbuzz for kerning and ligatures
libunibreak Use dev-libs/libunibreak for hyphenation
libutf8proc Use dev-libs/libutf8proc for manipulating unicode strings

crwx-ng

chm Support chm format
fribidi Support bidirectional text by dev-libs/fribidi
harfbuzz Use media-libs/harfbuzz for kerning and ligatures
libunibreak Use dev-libs/libunibreak for hyphenation
libutf8proc Use dev-libs/libutf8proc for manipulating unicode strings

dblatex

inkscape Use inkscape to convert SVG. Disable to use gnome-base/librsvg instead.

dictd

judy Build Judy-based (dev-libs/judy) plugin implementing fast "exact" and especially "lev" strategies
minimal Don't build server but dict client, dictzip and dictfmt only.

docbook-sgml-utils

jadetex Add support for processing tex files produced by the TeX backend of Jade

docbook-xsl-ns-stylesheets

ruby Install the Ruby-based dbtoepub script; requires an interpreter compatible with app-eselect/eselect-ruby.

docbook-xsl-stylesheets

ruby Install the Ruby-based dbtoepub script; requires an interpreter compatible with app-eselect/eselect-ruby.

doxygen

clang support for sys-devel/clang assisted parsing
dot allow to create dot graphs using media-gfx/graphviz
doxysearch build doxyindexer and doxysearch.cgi

ebook-tools

lit2epub Install lit2epub script

editorconfig-core-c

cli Install command line interface.

enchant

aspell Adds support for app-text/aspell spell checker
hunspell Adds support for app-text/hunspell spell checker
nuspell Adds support for app-text/nuspell spell checker
voikko Adds support for dev-libs/libvoikko spell checker

evince

dvi Enable the built-in DVI viewer
nautilus Enable property page extension in gnome-base/nautilus
postscript Enable support for PostScript and Adobe Illustrator documents with app-text/libspectre
spell Enable inline spell check for annotations via app-text/gspell
xps Enable XPS viewer using app-text/libgxps

feathernotes

X Link application against X11 libraries which adds support for virtual desktop awareness and tab DND

ghostscript-gpl

unicode Add support for unicode passwords via net-dns/libidn

groonga

abort Enable query abortion
benchmark Build benchmark programs
dynamic-malloc-change Allow dynamic memory allocation change for testing
exact-alloc-count Atomic counting for memory alloc count
fmalloc Make memory allocation failed in specified condition for debug
futex Use futex
libevent Enable dev-libs/libevent used for suggestion
mecab Use app-text/mecab for morphological analysis
msgpack Enable dev-libs/msgpack used for suggestion
nfkc Use nfkc based utf8 normalization
sphinx Enable document generation by app-misc/sphinx
uyield Build for detecting race conditions
zeromq Enable net-libs/zeromq used for suggestion

htmltidy

deprecated Install tools and header files which are now considered deprecated

hyperestraier

mecab Enable app-text/mecab support for Estraier

kbibtex

webengine Use dev-qt/qtwebengine for HTML previews

lcdf-typetools

kpathsea Enable integration with kpathsea search library (TeX related)

libebook

tools Build file conversion tools

libgepub

webkit Build with GepubWidget based on Webkit

libmwaw

tools Build file conversion tools

libqxp

tools Build file conversion tools

libstaroffice

tools Build conversion tools
zlib Enable support for compressed data

libwpd

tools Build file conversion tools

libwps

tools Build file conversion tools

mandoc

cgi build man.cgi web plugin for viewing man pages
system-man set as the default man provider

mathtex

png Generate png images by default instead of gif

msort

heap Use heap instead of alloca()
icu Use dev-libs/icu instead of dev-libs/libutf8proc.
libuninum Use dev-libs/libuninum for conversion.

mupdf

archive Enable support for CBR and other archive formats using libarchive

pandoc

embed-data-files Embed data files in binary for relocatable executable.
trypandoc Build trypandoc cgi executable.

pandoc-bin

pandoc-symlink Install pandoc symlink that points to pandoc-bin

pandoc-cli

lua Support custom modifications and conversions with the pandoc Lua scripting engine.
nightly Add '-nightly-COMPILEDATE' to the output of '--version'.
server Include support for running pandoc as an HTTP server.

pdfgrep

unac Removing accents and ligatures before search

pdfjam

extra Install unsupported wrapper scripts, for example pdf90, pdfnup, pdfjoin

pdfpc

gstreamer Compile support for movie playback (media-libs/gstreamer)
soup Compile support for REST server (net-libs/libsoup)
webkit Enable viewing Markdown notes (net-libs/webkit-gtk)

pelican

markdown Markdown support

podofo

boost Add support for boost
tools Build and install commandline tools.

poppler

boost Use boost::small_vector for a serious performance gain
gpgme Enable signatures handling with app-crypt/gpgme
nss Enable signatures handling with dev-libs/nss
utils Install command-line PDF converters and various utilities.

qpdfview

fitz Use experimental fitz rendering, provided by app-text/mupdf, instead of poppler
synctex Add support for searching TeX sources

robodoc

examples Installs usage examples in /usr/share for Perl

sdcv

darkterm Improve readability of color output on terminals with dark background.

sigil

plugins Installed needed Python packages for using Sigil plugins
system-mathjax Use the system-wide dev-libs/mathjax instead of bundled

sword

clucene Use dev-cpp/clucene for lucene search support

tessdata_best

osd Enable support orientation and script detection.

tessdata_fast

osd Enable support orientation and script detection.

tessdata_legacy

math Enable support for recognition of equations.
osd Enable support orientation and script detection.

tesseract

float32 Support float for model training and text recognition (faster, requires less RAM)
training Install training applications to add support for new languages.

texlive

context Add support for the ConTeXt format (dev-texlive/texlive-context)
extra Add support for extra TeXLive packages
games Add typesetting support for games (chess, etc.) (dev-texlive/texlive-games)
graphics Add support for several graphics packages (pgf, tikz,...)
humanities Add LaTeX support for the humanities (dev-texlive/texlive-humanities)
luatex Install TeX Live packages that require luatex
metapost Add support for metapost: A tool for creating graphics in scalable PostScript
music Add support for music typesetting (dev-texlive/texlive-music)
pdfannotextractor Add dev-tex/pdfannotextractor support, for extracting annotations from PDF files
pstricks Add pstricks packages (dev-texlive/texlive-pstricks)
publishers Add support for publishers (dev-texlive/texlive-publishers)
science Add typesetting support for natural and computer sciences (dev-texlive/texlive-mathscience)
tex4ht Add support for dev-tex/tex4ht (for converting (La)TeX to (X)HTML, XML and OO.org)
texi2html Add support for app-text/texi2html which converts texi files to HTML
xetex Add support for XeTeX macros (dev-texlive/texlive-xetex)

texlive-core

luajittex Add support for LuaJitTeX: LuaTeX based on LuaJIT which is usually faster.
xetex Add support for XeTeX: a TeX system with Unicode and modern font technologies.
xindy Add support for Xindy: A general-purpose index processor.

wdiff

experimental Build experimental utilities (mdiff, unify, wdiff2)

webgen

builder Enable programmatic HTML/XML generation
highlight Enable syntax highlighting for certain plugins
markdown Markdown support

writerperfect

abiword Add support for abiword format using app-text/libabw
ebook Add support for various ebook formats using app-text/libebook
epub Add support for conversion to ePub format using app-text/libepubgen
freehand Add support for freehand format using media-libs/libfreehand
gsf Add support for structured files using gnome-extra/libgsf
keynote Add support for keynote format using app-text/libetonyek
mspub Add support to mspub format using app-text/libmspub
mwaw Add support to mwaw formats using app-text/libmwaw
pagemaker Add support to pagemaker formats using media-libs/libpagemaker
qxp Add support for QuarkXpress documents using app-text/libqxp
visio Add support for visio format using media-libs/libvisio
wpd Add support for wpd format using app-text/libwpd
wpg Add support for wpg format using app-text/libwpg
wps Add support for wps format using app-text/libwps
zmf Add support for Zoner Callisto/Draw documents format using media-libs/libzmf

wv

tools Install optional utilities considered deprecated in favor of using AbiWord.

xmlto

text Support conversion from XML to plain text

xpdf

cmyk Include support for CMYK rasterization
i18n Enable support non-UTF8 national charsets
icons Generate desktop PNG icons using rsvg-convert from gnome-base/librsvg
libpaper Use app-text/libpaper to get paper preferences
metric Use A4 instead of US Letter paper size by default for PostScript output. This option has effect only if libpaper USE flag is disabled
opi Include support for OPI (Open Prepress Interface) comments
textselect Allow text selection
utils Install command-line PDF converters and various utilities

zathura

synctex Use libsynctex to get latex codeline from pdf

zathura-meta

cb Install plug-in for ComicBook support

zeal

X Enable global shortcut support on X11

app-vim

gentoo-syntax

ignore-glep31 Remove GLEP 31 (UTF-8 file encodings) settings

app-xemacs

xemacs-packages-all

mule Add multi-language support to XEmacs

dev-ada

AdaSAT

shared Build shared library
static-pic Build static library with pic code

VSS

shared Build shared library
static-pic Build static library with pic code

aws

shared Build shared library
wsdl Used to convert ada to wsdl

gnatcoll-bindings

shared Build shared library
static-pic Build shared library

gnatcoll-core

shared Build shared library
static-pic Build static library with pic code

gnatcoll-db

db2ada Build gnatcoll_db2ada
gnatinspect Build gnatinspect
shared Build shared library
sql Build sql library
static-pic Build shared library
xref Build xref library

gpr

shared Build shared library
static-pic Build static library with pic code

gpr-unit-provider

shared Build shared library
static-pic Build static library with pic code

gtkada

shared Build gtkada as shared library
static-pic Build static library with pic code

lal-refactor

shared Build shared library
static-pic Build static library with pic code

langkit

shared Build shared library
static-pic Build static library with pic code

libadalang

static-pic Build static library with pic code

libadalang-tools

shared Build shared library
static-pic Build static library with pic code

libgpr

shared Build shared library
static-pic Build static library with pic code

spawn

glib Add support to dev-libs/glib-based mainloop.
shared Build shared library
static-pic Build static library with pic code

templates-parser

shared Build shared library

xmlada

shared Build shared library
static-pic Build static library with pic code

dev-build

bazelisk

bazel-symlink Install bazel symlink that points to bazelisk

cmake

dap Build debugger for CMake with Debug Adapter Protocol support via dev-cpp/cppdap

muon

archive Enable extracting wraps using app-arch/libarchive.
libpkgconf Enable looking up packages via dev-util/pkgconf.

dev-cpp

benchmark

exceptions Enable the use of exceptions in the benchmark library
libcxx Use sys-libs/libcxx instead of libstdc++ as the default stdlib
libpfm Enable dev-libs/libpfm support
tools Install some additional Python tools

eigen

adolc Add test support for Adolc (sci-libs/adolc)
benchmark Build benchmark suite
boost Add test support for Boost.Multiprecision (dev-libs/boost)
cholmod Add test support for CHOLMOD (sci-libs/cholmod)
clang Use clang for cuda units compilation
fftw Add test support for fftw (sci-libs/fftw)
hip Enable HIP GPU computing support
klu Add test support for KLU (sci-libs/klu)
mathjax Use MathJax for rendering math in HTML docs (dev-libs/mathjax)
opengl Add test support for OpenGL
openmp Add test support for the OpenMP (support parallel computing)
pastix Add test support for PaStiX (sci-libs/pastix)
sparsehash Add test support for GoogleHash (dev-cpp/sparsehash)
spqr Add test support for SPQR (sci-libs/spqr)
superlu Add test support for SuperLU (sci-libs/superlu)
umfpack Add test support for UMFPACK (sci-libs/umfpack)

glog

gflags Use dev-cpp/gflags for flag parsing
libunwind Use libunwind library (sys-libs/libunwind or sys-libs/llvm-libunwind) instead of built-in fallback implementation for stack unwinding

gtest

abseil Build with functionality provided by dev-cpp/abseil-cpp and dev-libs/re2

jwt-cpp

picojson Enable use of dev-cpp/picojson

libcmis

tools Build client tool for testing and viewing features

libjson-rpc-cpp

http-client Build support for HTTP client using net-misc/curl
http-server Build support for HTTP server using net-libs/libmicrohttpd
redis-client Build support for Redis client using dev-libs/hiredis
redis-server Build support for Redis server using dev-libs/hiredis
stubgen Build header stub code generator (needed for development and when pregenerated headers are not bundled)

msgpack-cxx

boost Enable boost support

opentelemetry-cpp

jaeger Include the jaeger exporter
prometheus include the Prometheus Client in the SDK

sdbus-c++

systemd Use external libsystemd instead of statically-linked build
tools Install interface stub code generator

dev-db

etcd

server Installs etcd daemon

firebird

server Install the server components of Firebird, not just the client
xinetd Install ClassicServer

mariadb

backup Build mariadb-backup which supports SST and hot backup of InnoDB, Aria and MyISAM including compression and encryption
columnstore Build the ColumnStore storage engine
extraengine Add support for alternative storage engines (Archive, CSV, Blackhole, Federated(X), Partition)
galera Enables galera replication
innodb-lz4 Enables lz4 compression methods for InnoDB/XtraDB
innodb-lzo Enables lzo compression methods for InnoDB/XtraDB
innodb-snappy Enables snappy compression methods for InnoDB/XtraDB using app-arch/snappy
jdbc Enable the CONNECT engine to access foreign databases via JDBC
latin1 Use LATIN1 encoding instead of UTF8
mroonga Add support for the Mroonga engine for interfacing with the Groonga text search
numa Enable NUMA support using sys-process/numactl (NUMA kernel support is also required)
oqgraph Add support for the Open Query GRAPH engine
pam Enable the optional PAM authentication plugin for the server
profiling Add support for statement profiling (requires USE=community).
rocksdb Add support for RocksDB; a key/value, LSM database optimized for flash storage
s3 Build the S3 storage engine
server Build the server program
sphinx Add suport for the sphinx full-text search engine
sst-mariabackup Add tools needed to support the mariabackup SST method
sst-rsync Add tools needed to support the rsync SST method
systemtap Build support for profiling and tracing using dev-debug/systemtap
test Install upstream testsuites for end use.
yassl Enable SSL connections and crypto functions using the bundled yaSSL

mongodb

mongosh Install the MongoDB shell from app-admin/mongosh-bin
tools Install the MongoDB tools (mongoimport, mongodump...) from app-admin/mongo-tools

mycli

ssh Add support for connection over SSH tunnel

mysql

cjk Add CJK support for InnoDB fulltext search using app-text/mecab
client-libs Build the client libraries from the server package instead of the C Connector packages (not recommended)
experimental Build experimental features aka "rapid" plugins
latin1 Use LATIN1 encoding instead of UTF8
numa Enable NUMA support using sys-process/numactl (NUMA kernel support is also required)
profiling Add support for statement profiling (requires USE=community).
router Build the MySQL router program
server Build the server program
systemtap Build support for profiling and tracing using dev-debug/systemtap
test Install upstream testsuites for end use.

mysql-connector-c++

legacy Build the legacy 1.x API as well as the DevX API

oracle-instantclient

jdbc Support for XA, Internationalization, and RowSet operations under JDBC
odbc Libraries for enabling ODBC applications
precomp "proc" binary and related files to precompile a Pro*C application
sdk Header files and an example makefile for developing Oracle applications
sqlplus The SQL*Plus command line tool for SQL and PL/SQL queries
tools Data Pump, SQL*Loader and Workload Replay Client

percona-server

cjk Add CJK support for InnoDB fulltext search using app-text/mecab
latin1 Use LATIN1 encoding instead of UTF8
numa Enable NUMA support using sys-process/numactl (NUMA kernel support is also required)
profiling Add support for statement profiling (requires USE=community).
rocksdb Add support for RocksDB; a key/value, LSM database optimized for flash storage
router Build the MySQL router program
server Build the server program
tokudb Add support for TokuDB storage engine
tokudb-backup-plugin Builds the TokuDB backup plugin

pgbouncer

c-ares Use c-ares as the DNS backend instead of evdns (libevent).
udns Use udns as the DNS backend instead of evdns (libevent). Supports IPv4 only.

pgpool2

memcached Use memcached for query caching.

phpmyadmin

setup Installs the phpMyAdmin setup utility. Users who don't use the utility should disable this USE flag for security reasons as the setup tool was the target of various exploits in the past.

postgis

address-standardizer Normalize US and CA postal addresses
gtk Build graphical interface for shp2pgsql (shp2pgsql-gui)
topology Build topology spatial types and functions

postgresql

llvm Add support for llvm JIT engine
server Disable to build and install the clients and libraries only.
uuid Enable server side UUID generation (via dev-libs/ossp-uuid).

psqlodbc

iodbc Use dev-db/libiodbc. Disable to use dev-db/unixODBC.

recutils

curl Enable support for remote descriptors using net-misc/curl
mdb Build the mdb2rec utility using app-office/mdbtools

redict

tcmalloc Use tcmalloc from dev-util/google-perftools for allocations.

redis

tcmalloc Use tcmalloc from dev-util/google-perftools for allocations.

spatialite

geos Add the sci-libs/geos library for exact topological tests
proj Add the sci-libs/proj library for reprojection features
rttopo Add the sci-geosciences/librttopo library for topology support
xls Add the dev-libs/freexl library for xls import support

sqldeveloper

sybase Add support for the Sybase SQL Database Server

sqlite

secure-delete Enable overwriting of deleted content with zeros by default (http://sqlite.org/pragma.html#pragma_secure_delete), causing some performance penalty
tools Install additional tools, among which are included: sqlite3-analyzer, sqlite3-changeset, sqlite3-db-dump, sqlite3-diff, sqlite3-rbu, sqlite3-expert and others.

sqlitebrowser

sqlcipher Allow to open and to edit databases encrypted using dev-db/sqlcipher

sqlitestudio

cli Build CLI interface

timescaledb

proprietary-extensions Enable proprietary features/extensions licensed under the TimeScale License

unixODBC

minimal Disable bundled drivers and extra libraries (most users don't need these)
odbcmanual Administrator, Internal Structure, Programmer and User documentation

dev-debug

bpftrace

fuzzing Build bpftrace for fuzzing
lldb Parse debug info usingdev-debug/lldb

dtrace

test-install Install the testsuite for manual use. It is not suitable for automatic execution within the ebuild because it requires root privlieges.

gdb

cet Enable Intel Control-flow Enforcement Technology.
debuginfod Enable debuginfod support via dev-libs/elfutils libdebuginfod
lzma Support lzma compression in ELF debug info
multitarget Support all known targets in one gdb binary
python Enable support for the new internal scripting language, as well as extended pretty printers
server Install the "gdbserver" program (useful for embedded/remote targets)
sim Build gdb's simulators for various hardware platforms. See https://sourceware.org/gdb/wiki/Sim.
source-highlight Enable listing highlighting via dev-util/source-highlight
xml Support parsing XML data files needed (at least) for cpu features, memory maps, and syscall tracing
xxhash Use dev-libs/xxhash to speed up internal hashing.

lldb

debuginfod Expose the transitive dependencies on net-misc/curl and dev-cpp/cpp-httplib) to match sys-devel/llvm.

ltrace

elfutils Use libdwfl from dev-libs/elfutils for frame unwinding support
unwind Use sys-libs/libunwind for frame unwinding support

strace

aio Enable dev-libs/libaio support for tracing Asynchronous I/O operations
elfutils Enable stack backtraces (-k flag) via dev-libs/elfutils
unwind Enable stack backtraces (-k flag) via sys-libs/libunwind

sysdig

bpf Enable the BPF probe as alternative event source to dev-debug/scap-driver.
modules Build kernel modules needed for tracing local events. Disable this only if you intend to use sysdig purely to work with dumpfiles.

systemtap

debuginfod Enable debuginfod support via dev-libs/elfutils libdebuginfod
dtrace-symlink Provide /usr/bin/dtrace symlink pointing to /usr/bin/stap-dtrace. This prevents coinstallation with dev-debug/dtrace.
libvirt Support probing of libvirt domains.

dev-embedded

avrdude

ftdi Enable support for USB FTDI chips via dev-embedded/libftdi

libftdi

tools build ftdi_eeprom helper tool

openocd

capstone Use dev-libs/capstone for disassembly support
cmsis-dap Support for CMSIS-DAP compliant adapters
dummy Build the dummy port driver
ftdi Enable support for USB FTDI chips via dev-embedded/libftdi
gpiod Enable Linux GPIO bitbang support via libgpiod
jlink Build the SEGGER J-Link driver
parport Enable support for parport JTAG devices
verbose-io Verbose IO and comm JTAG and USB messages

rpi-eeprom

pi4 Install firmware files for the Raspberry Pi 4
pi5 Install firmware files for the Raspberry Pi 5

sdcc

boehm-gc Enable Hans Boehm's garbage collector dev-libs/boehm-gc
device-lib Enable built of devices libraries
ds390 Add support for Dallas DS390
ds400 Add support for Dallas DS400
ez80-z80 Add support for EZ80-Z80
hc08 Add support for Freescale/Motorola HC08 based
mcs51 Add support for Intel mcs51
mos6502 Add support for MOS 6502
mos65c02 Add support for MOS 65C02
non-free Enable non-free runtime library parts
packihx Enable Intel HEX files pack utility
pdk13 Add support for PDK13
pdk14 Add support for PDK14
pdk15 Add support for PDK15
pdk16 Add support for PDK16
pic14 Add support for Microchip 14 bits PICs
pic16 Add support for Microchip 16 bits PICs
r2k Add support for Rabbit 2000
r2ka Add support for Rabbit 2000A
r3ka Add support for Rabbit 3000A
s08 Add support for Freescale/Motorola S08
sdcdb Enable SDCC source level debugger
sdcpp Enable SDCC preprocessor based on GCC cpp
sm83 Add support for Gameboy SM83
stm8 Add support for STMicroelectronics STM8
tlcs90 Add support for TLCS-90
ucsim Enable software simulator for microcontrollers
z180 Add support for Zilog Z180
z80 Add support for Zilog Z80
z80n Add support for Zilog Z80N

u-boot-tools

envtools Build only the target-side environment tools

urjtag

ftd2xx Enable support for USB FTDI chips via dev-embedded/libftd2xx
ftdi Enable support for USB FTDI chips via dev-embedded/libftdi

dev-games

godot

deprecated Enable support for deprecated features
raycast Enable the raycast Editor module using media-libs/embree
tools Enable the Godot Editor for game development

guichan

allegro Build the Allegro frontend

mygui

l10n_ru Install some additional russian docs if 'doc' useflag enabled
ogre Use the ogre render subsystem. (cannot combine with opengl)
opengl Use the opengl render subsystem. (cannot combine with ogre)
plugins Build MyGUI plugins
samples Install MyGUI demos (needs ogre USE flag)
tools Build the tools for development

ode

double-precision more precise calculations at the expense of speed
gyroscopic enable gyroscopic term (may cause instability)

ogre

assimp Use media-libs/assimp to import assets from 3D files
boost Enable boost support
bullet Use sci-physics/bullet for physics plugin
cache Enable GL state cache support
cg NVIDIA toolkit plugin
deprecated Build deprecated nodeless positioning of Lights and Cameras.
double-precision More precise calculations at the expense of speed
egl Use egl instead of glx
fine-granularity Enable fine light mask granularity. This impacts on performance and should not be enabled unless an application really needs it.
freeimage Support images via media-libs/freeimage
gl3plus Build OpenGL 3+ RenderSystem
gles3 Enable OpenGL ES 3.x Features
json Use dev-libs/rapidjson (needed by Hlms JSON materials)
legacy-animations Use the skeletal animation from 1.x. It's much slower, but the new system is still experimental.
ois Pull in Object-oriented Input System library dev-games/ois for samples
poco When USE=threads, use poco for threading
resman-pedantic Resource Manager PEDANTIC : require an explicit resource group. Case sensitive lookup. Some demos might not work with this setting. (default: case-insensitive + sensitive lookup in all groups)
tbb When USE=threads, use tbb for threading
tools Build and install AssimpConverter (assimp USE flag is enabled), MeshUpgrader, VRMLConverter and XMLConverter

openscenegraph

collada Enable DAE file support via dev-libs/collada-dom
dicom Enable DICOM medical image file support via sci-libs/dcmtk
fox Build examples using x11-libs/fox library
gdal Enable support for sci-libs/gdal library
las Enable support for geospatial data LAS LiDAR format using sci-geosciences/liblas
openinventor Build OpenInventor plugin
osgapps Build osg applications
sdl2 Use media-libs/libsdl2 additionally to media-libs/libsdl
xrandr Enable support for the X xrandr extension

openscenegraph-openmw

collada Enable DAE file support via dev-libs/collada-dom
dicom Enable DICOM medical image file support via sci-libs/dcmtk
fox Build examples using x11-libs/fox library
gdal Enable support for sci-libs/gdal library
las Enable support for geospatial data LAS LiDAR format using sci-geosciences/liblas
openinventor Build OpenInventor plugin
osgapps Build osg applications
sdl2 Use media-libs/libsdl2 additionally to media-libs/libsdl
xrandr Enable support for the X xrandr extension

physfs

7zip Enable 7zip/lzma archive support
grp Enable Build Engine GRP archive support
hog Enable Descent I/II HOG archive support
iso Enable ISO9660 file support
mvl Enable Descent I/II MVL archive support
qpak Enable Quake I/II QPAK archive support
slb Enable Independence War SLB archive support
vdf Enable Gothic/Gothic II VDF archive support
wad Enable Doom WAD archive support

simgear

dns Enable DNS resolver via net-libs/udns
gdal Enable alternative terrain engine based on pagedLOD via sci-libs/gdal
subversion Enable terrasync scenery downloader

tiled

minimal Exclude optional plugins and development headers

dev-gap

grape

bliss Use sci-libs/bliss instead of sci-mathematics/nauty as the backend.

dev-haskell

abstract-deque

usecas Enable the reference implementation to use hardware compare-and-swap.

aeson

cffi Controls whether to include c-ffi bits or pure haskell. Default to False for security.
ordered-keymap Use ordered @Data.Map.Strict@ for KeyMap implementation.

aeson-pretty

executable build/install the command-line tool as well as the library
lib-only don't build 'aeson-pretty' executable.

ansi-terminal

example Build the example application

assoc

tagged You can disable the use of the `tagged` package using `-f-tagged`. Disabing this is an unsupported configuration, but it may be useful for accelerating builds in sandboxes for expert users.

atomic-primops

debug Enable extra internal checks.

bifunctors

semigroups You can disable the use of the `semigroups` package using `-f-semigroups`. Disabing this is an unsupported configuration, but it may be useful for accelerating builds in sandboxes for expert users.
tagged You can disable the use of the `tagged` package using `-f-tagged`. Disabing this is an unsupported configuration, but it may be useful for accelerating builds in sandboxes for expert users.

bitvec

gmp Link against the GMP library for the ultimate performance of `zipBits`, `invertBits` and `countBits`. Users are strongly encouraged to enable this flag whenever possible.

boring

tagged You can disable the use of the `tagged` package using `-f-tagged`. Disabling this is an unsupported configuration, but it may be useful for accelerating builds in sandboxes for expert users.

c2hs

regression Enable regression suite build.

cabal-install

lukko Use @lukko@ for file-locking
native-dns Enable use of the [resolv](https://hackage.haskell.org/package/resolv) & [windns](https://hackage.haskell.org/package/windns) packages for performing DNS lookups

cairo

svg Build the Scalable Vector Graphics (SVG) backend of Cairo.

chell

color-output use colors in program output

citeproc

executable Build citeproc executable
icu Use Haskell bindings to the ICU library

cmdargs

examples Build the cmdargs-demo program
quotation Build the Quote module
testprog Build the test program

comonad

indexed-traversable You can disable the use of the `indexed-traversable` package using `-f-indexed-traversable`. Disabling this is an unsupported configuration, but it may be useful for accelerating builds in sandboxes for expert users. If disabled we will not supply instances of `FunctorWithIndex`

contravariant

semigroups You can disable the use of the `semigroups` package using `-f-semigroups`. Disabling this is an unsupported configuration, but it may be useful for accelerating builds in sandboxes for expert users.
statevar You can disable the use of the `StateVar` package using `-f-StateVar`. Disabling this is an unsupported configuration, but it may be useful for accelerating builds in sandboxes for expert users.
tagged You can disable the use of the `tagged` package on older versons of GHC using `-f-tagged`. Disabling this is an unsupported configuration, but it may be useful for accelerating builds in sandboxes for expert users.

criterion

embed-data-files Embed the data files in the binary for a relocatable executable. (Warning: This will increase the executabl size significantly.)

crypto-api

all-cpolys Build all the CMAC polynomes up to 10000 bits instead of just the usual ones

cryptohash-sha256

executable Build the cryptohash-sha256sum executable

crypton

check-alignment extra check on alignment in C layers, which cause lowlevel assert errors. for debugging only.
integer-gmp Whether or not to use GMP for some functions
old-toolchain-inliner use -fgnu89-inline to workaround an old compiler / linker / glibc issue.
support-aesni allow compilation with AESNI on system and architecture that supports it
support-deepseq add deepseq instances for cryptographic types
support-pclmuldq Allow compilation with pclmuldq on architecture that supports it
support-rdrand allow compilation with RDRAND on system and architecture that supports it
support-sse Use SSE optimized version of (BLAKE2, ARGON2)
target-attributes use GCC / clang function attributes instead of global target options.

cryptonite

integer-gmp Whether or not to use GMP for some functions
target-attributes use GCC / clang function attributes instead of global target options.

dlist

werror Enable -Werror

doctest-driver-gen

executable Build the doctest-driver-gen executable

entropy

donotgetentropy Avoid use of the getentropy() *nix function. By default getentropy will be used if detected during compilation (this plays poorly with cross compilation).
halvm Build for the HaLVM.

foldable1-classes-compat

tagged You can disable the use of the `tagged` package using `-f-tagged`. Disabling this is an unsupported configuration, but it may be useful for accelerating builds in sandboxes for expert users.

foundation

experimental Enable building experimental features, known as highly unstable or without good support cross-platform

glib

closure-signals Use the the GClosure-based signals implementation.

gtk2hs-buildtools

closuresignals Use the the GClosure-based signals implementation.

hackage-security

lukko Use @lukko@ for file-locking, otherwise use @GHC.IO.Handle.Lock@

hashable

random-initial-seed Randomly initialize the seed on every executable invocation. This is not a security feature and is intended only for testing (it can affect legitimate use cases).

hashtables

bounds-checking if on, use bounds-checking array accesses
detailed-profiling add detailed profiling information to profiled build-depends

haskeline

terminfo Use the terminfo package for POSIX consoles.

hdbc-sqlite3

splitbase Choose the new smaller, split-up package.

hslua-cli

executable Compile `hslua` standalone executable.

hslua-repl

executable Compile `luarepl` standalone executable.

hsyaml

exe Enable @exe:yaml-test@ component

http-api-data

text-show Use text-show library for efficient ToHttpApiData implementations.

httpd-shed

buildexamples Build example executables.

juicypixels

mmap Enable the file loading via mmap (memory map)

libyaml

system-libyaml Use the system-wide libyaml instead of the bundled copy
unicode Enable unicode output. Otherwise, unicode characters will be escaped.

lpeg

rely-on-shared-lpeg-library Do not build lpeg from source, but trust that lpeg is made available in other ways, e.g., through a system-wide installation. The loader will be replaced with a placeholder function that only emits a message.

lua

system-lua Use @pkg-config@ to discover library and include paths. Setting this flag implies `pkg-config`.

markdown-unlit

executable Build executable

monad-logger

template-haskell Enable Template Haskell support

monad-par

chaselev Use Chase-Lev Deques for higher-perf work-stealing.

nats

binary enable binary instances
hashable enable hashable instances
template-haskell enable template_haskell

network

devel using tests for developers

nothunks

bytestring Provide instances for bytestring
text Provide instances for text
vector Provide instances for vector

pandoc

embed-data-files Embed data files in binary for relocatable executable.

parsec-numbers

parsec1 use dev-haskell/parsec1 instead of dev-haskell/parsec

parsers

attoparsec You can disable the use of the `attoparsec` package using `-f-attoparsec`.
binary You can disable the use of the `binary` package using `-f-binary`.
parsec You can disable the use of the `parsec` package using `-f-parsec`.

persistent-sqlite

build-sanity-exe Build a sanity check test executable

prettyprinter

buildreadme Build the readme generator
text While it's a core value of @prettyprinter@ to use @Text@, there are rare circumstances (mostly when @prettyprinter@ arises as a dependency of test suites of packages like @bytestring@ or @text@ themselves) when this is inconvenient. In this case one can disable this flag, so that @prettyprinter@ fallbacks to @String@.

quickcheck

template-haskell Build Test.QuickCheck.All, which uses Template Haskell.

quickcheck-classes

aeson You can disable the use of the `aeson` package using `-f-aeson`. This may be useful for accelerating builds in sandboxes for expert users.
binary-laws Include infrastructure for testing class laws of binary type constructors. It is required that this flag match the value that the `unary-laws` flag was given when building `quickcheck-classes-base`. Disabling `unary-laws` while keeping `binary-laws` enabled is an unsupported configuration.
semigroupoids You can disable the use of the `semigroupoids` package using `-f-semigroupoids`. This may be useful for accelerating builds in sandboxes for expert users.
semirings You can disable the use of the `semirings` package using `-f-semirings`. This may be useful for accelerating builds in sandboxes for expert users.
unary-laws Include infrastructure for testing class laws of unary type constructors. It is required that this flag match the value that the `unary-laws` flag was given when building `quickcheck-classes-base`.
vector You can disable the use of the `vector` package using `-f-vector`. This may be useful for accelerating builds in sandboxes for expert users.

quickcheck-classes-base

binary-laws Include infrastructure for testing class laws of binary type constructors. Disabling `unary-laws` while keeping `binary-laws` enabled is an unsupported configuration.
unary-laws Include infrastructure for testing class laws of unary type constructors.

random-bytestring

pcg compile with support for PCG from pcg-random

sandi

conduit Build with conduit

semialign

semigroupoids Build with semigroupoids dependency

sha

exe Build a sha1 and a sha384 executable similar to 'md5sum'.

shelly

lifted run the tests against Shelly.Lifted

simple-sendfile

allow-bsd Allow use of BSD sendfile (disable on GNU/kFreeBSD)

skein

big-endian When manually selecting the endianness, use big-endian (default is little-endian).
force-endianness Use a manually selected endian when compiling (see flag 'big-endian').
reference Use the reference implementation instead of the optimized one.

skylighting

executable Whether to build the skylighting program

skylighting-core

executable Build skylighting-extract tool

some

newtype-unsafe Use implementation using @newtype@ and unsafe @Any@, instead of GADT

splitmix

optimised-mixer Use JavaScript for mix32

tasty

clock Depend on the clock package for more accurate time measurement

texmath

executable Compile test executable.
server Compile webserver.

text-short

debug Enable runtime-checks via 'assert'

tls

compat Accept SSLv2 client hello for beginning SSLv3 / TLS handshake
network Use the base network library

transformers-base

orphaninstances Build instances for orphan datatypes.

typst

executable Compile executable to be used in testing and development.

unicode-collation

doctests Run doctests as part of test suite. Use with: @--write-ghc-environment-files=always@.
executable Build the unicode-collate executable.

unix-compat

old-time build against old-time package

vector

boundschecks Enable bounds checking
internalchecks Enable internal consistency checks at the cost of a significant performance penalty
unsafechecks Enable bounds checking in unsafe operations at the cost of a significant performance penalty

vector-algorithms

bench Build a benchmarking program to test vector-algorithms performance
boundschecks Enable bounds checking
internalchecks Enable internal consistency checks at the cost of a significant performance penalty.
properties Enable the quickcheck tests
unsafechecks Enable bounds checking in unsafe operations at the cost of a significant performance penalty.

void

safe dissable effective but unsafe coersions

wai-app-static

print print debug info.

warp

allow-sendfilefd Allow use of sendfileFd (not available on GNU/kFreeBSD)
x509 Adds a dependency on the x509 library to enable getting TLS client certificates.

wcwidth

cli Enable command line tool

yaml

executable Install the yaml2json and json2yaml executables

yesod-form

network-uri Get Network.URI from the network-uri package

zip-archive

executable Build the Zip executable.

zlib

bundled-c-zlib Use the bundled zlib C sources. Requires pkg-config to be False. For windows, this is the default.
non-blocking-ffi The (de)compression calls can sometimes take a long time, which prevents other Haskell threads running. Enabling this flag avoids this unfairness, but with greater overall cost.

dev-java

ant

antlr Enable ANTLR Ant tasks
bcel Enable bcel (bytecode manipulation) Ant tasks
bsf Enable support for Apache Bean Scripting Framework (dev-java/bsf)
commonslogging Enable commons-logging Ant tasks
commonsnet Enable commons-net Ant tasks
imageio Enable imageio Ant tasks
jai Enable JAI (Java Imaging) Ant task
jakartamail Enable Jakartamail Ant task
javamail Enable JavaMail Ant task
jdepend Enable Jdepend Ant tasks
jmf Enable JMF (Java Media Framework) Ant tasks
jsch Disable Jsch (ssh, scp and related) Ant tasks
junit Enable JUnit Ant tasks
junit4 Enable JUnit4 Ant tasks
junitlauncher Enable JUnit5 Ant tasks
log4j Enable Apache log4j Ant tasks
oro Enable Apache Oro Ant tasks
regexp Enable Apache Regexp Ant tasks
resolver Enable Apache Resolver Ant tasks
swing Enable Swing Ant tasks
testutil Enable optional test util classes
xalan Enable Apache Xalan2 Ant tasks
xz Enable XZ Ant tasks

commons-logging

log4j Add optional support for log4j

dom4j

jaxen Includes org.jaxen.dom4j package

emma

launcher Install /usr/bin/emma. Collides with sci-biology/emboss.

java-config

compat Install bin/java-config-2 symlink pointing to java-config

javacup

ant-task Build and register the ant-task

jaxen

dom4j Includes org.jaxen.dom4j package
jdom Includes org.jaxen.jdom package
xom Includes org.jaxen.xom package

jflex

ant-task Build and register the ant-task

junit

migration-support Include the junit-jupiter-migrationsupport module, which helps with migration from JUnit 4 to JUnit Jupiter
suite Include the JUnit Platform Suite Engine, which adds test suite support
vintage Include JUnit Vintage, which allows JUnit 5 to run JUnit 3 and JUnit 4 tests

openjdk

headless-awt Don't install the X backend for AWT, needed by some GUIs
javafx Import OpenJFX modules at build time, via dev-java/openjfx
jbootstrap Build OpenJDK twice, the second time using the result of the first
source Install JVM sources
system-bootstrap Bootstrap using installed openjdk
systemtap Enable SystemTap/DTrace tracing

openjdk-bin

headless-awt Don't install the X backend for AWT, needed by some GUIs (used to be X flag)
source Install JVM sources

openjdk-jre-bin

headless-awt Don't install the X backend for AWT, needed by some GUIs (used to be X flag)

openjfx

media Compile media module, based on gstreamer-minimal (does not pull gstreamer)
source Install JavaFX sources

pdfbox

tools Build and install pdfbox-tools

protobuf-java

system-protoc Use protoc provided by dev-libs/protobuf

qdox

ant-task Build the ant-task

rxtx

lfd Installs and uses LockFileServer daemon (lfd)

saxon

ant-task BUILD and register the ant-task

sbt

binary Install from (Gentoo-compiled) binary instead of building from sources. Set this when you run out of memory during build.

dev-lang

R

libdeflate Use app-arch/libdeflate rather than sys-libs/zlib for lazy-loaded R objects.

algol68g

mpfr Add support for multiprecision floating point rouding

ammonite-repl-bin

scala2-13 Install Ammonite for Scala 2.13
scala3-0 Install Ammonite for Scala 3.0
scala3-1 Install Ammonite for Scala 3.1
scala3-2 Install Ammonite for Scala 3.2

bas

lr0 Use the LR0 parser instead of the recursive descending parser

crystal

debug Build each module as a separate object file. Speeds build up.

erlang

kpoll Enable kernel polling support

gdl

eigen Build matrix manipulation with dev-cpp/eigen
glpk Use GNU Linear Programming Kit sci-mathematics/glpk
gshhs Add support for projection adn continent maps with sci-geosciences/gshhs-data
hdf Add support for the Hierarchical Data Format v.4
proj Add support for sci-libs/proj (geographic projections)
shapelib Add support for manipulating ESRI Shapefiles with sci-libs/shapelib
udunits Add support for manipulating units of physical quantities

gforth

check Enable build-time sanity check.

ghc

binary Install the binary version directly, rather than using it to build the source version.
elfutils Enable DWARF-based backtraces using dev-libs/elfutils.
ghcbootstrap Internal: Bootstrap GHC from an existing GHC installation.
ghcmakebinary Internal: Build binary friendly for redistribution.
gmp Use dev-libs/gmp for integer operations (works faster, but an external depend).
llvm Pull in dependencies for the sys-devel/llvm codegen backend.
numa Enable NUMA thread balancing policy using sys-process/numactl.
unregisterised Create an unregisterised build in which only the C codegen backend will be available.

gnat-gpl

ada Build the ADA language (GNAT) frontend
cet Enable support for Intel Control Flow Enforcement Technology (CET)
d Enable support for the D programming language
default-stack-clash-protection Build packages with stack clash protection on by default
default-znow Request full relocation on start from ld.so by default
fixed-point Enable fixed-point arithmetic support for MIPS targets in gcc (Warning: significantly increases compile time!)
go Build the GCC Go language frontend.
graphite Add support for the framework for loop optimizations based on a polyhedral intermediate representation
libssp Build SSP support into a dedicated library rather than use the code in the C library (DO NOT ENABLE THIS IF YOU DON'T KNOW WHAT IT DOES)
modula2 Build the GCC Modula-2 language frontend.
objc Build support for the Objective C code language
objc++ Build support for the Objective C++ language
objc-gc Build support for the Objective C code language Garbage Collector
pgo Build GCC using Profile Guided Optimization (PGO)
rust Build support for the Rust language, installs gccrs.
sanitize Build support for various sanitizer functions (ASAN/TSAN/etc...)
ssp Build packages with stack smashing protector on by default
system-bootstrap Bootstrap using installed Ada compiler
systemtap enable systemtap static probe points
vtv Build support for virtual table verification (a C++ hardening feature)

gnucobol

json Enable support for JSON template formatting via dev-libs/json-c

idris2

chez build using dev-scheme/chez
racket build using dev-scheme/racket
test-full pull in depedndencies to run all tests

inform

tools Install blorbtools for manipulating Blorb files

ispc

gpu Enable Level0 GPU support in ispcrt.
openmp Build with OpenMP task model (otherwise, TBB task model is used).

janet

static-libs install janet static library archive, you must enable this flag for using `jpm build`

jerryscript

debugger Install jerry-debugger

jsonnet

custom-optimization Build with user-specified compiler optimizations (-Os, -O0, -O1, -O2, -O3) from CFLAGS (unsupported)

lazarus

extras Build a lot of extra packages, including lhelp chm viewer program.
gtk2 Use gtk:2 for widgets.
gui Build GUI IDE.
minimal Don't build extra packages from the bigide component

logtalk

fop Support for generating pdf documentation using fop
xslt Support for generating html documentation using xslt

lua

deprecated make deprecated data structures/routines available

luajit

lua52compat Enable some upwards-compatible features from Lua 5.2 that are unlikely to break existing code.

mercury

trail Support Mercury trail grades

mercury-extras

tommath Enable support for tommath library

mlton

binary install a binary version
bootstrap-smlnj Boostrap mlton with dev-lang/smlnj (takes a long time)
pax-kernel Enable if the user plans to run the package under a pax enabled hardened kernel
stage3 After bootstrap building mlton with dev-lang/smlnj, rebuild mlton with the second stage build of mlton (recommended).

moarvm

asan Enable clang's Address Sanitizer functionality. Expect longer compile time.
clang Use clang compiler instead of GCC
jit Enable Just-In-Time-Compiler. Has no effect except on AMD64 and Darwin.
optimize Enable optimization via CFLAGS
ubsan Enable clang's Undefined Behavior Sanitizer functionality. Expect longer compile time.

mono

pax-kernel Enable if the user plans to run the package under a pax enabled hardened kernel
xen Make mono generate code that is considerably faster on xen VMs but slightly slower on for normal systems.

neko

apache Build Apache modules

nim

test-js Enable tests that require Node.js

nqp

clang Toggle usage of the clang compiler in conjunction with MoarVM
moar Build the MoarVM backend (experimental/broken)

ocaml

flambda Enables the Flambda optimizer: A new intermediate representation (introduced in ocaml 4.03) in the depths of the compiler designed to allow for better inlining.
spacetime Enables the Spacetime memory profiler. See https://caml.inria.fr/pub/docs/manual-ocaml/spacetime.html for more information.

php

apparmor Support FPM application confinement through sys-libs/libapparmor
argon2 Enable password hashing algorithm from app-crypt/argon2
bcmath Enable the BCMath Arbitrary Precision Mathematics extension
capstone Support opcache JIT disassembly through dev-libs/capstone
cli Enable the Command-Line Interface (CLI) SAPI
coverage Include gcov symbols for test coverage and lcov reports. Only useful for extension developers, and requires GCC.
ctype Enable the Character type checking (ctype) extension
embed Enable embed SAPI
enchant Enable the Enchant spelling library extension using app-text/enchant
ffi Enable the Foreign Function Interface (FFI) extension using dev-libs/libffi
fileinfo Enable the File Information extension
filter Enable the Data Filtering extension
flatfile Add dbm support for flat files
fpm Enable the FastCGI Process Manager SAPI
gd Enable the Image Processing and GD extension (requires media-libs/libjpeg-turbo and media-libs/libpng)
inifile Add dbm support for .ini files
intl Enables the intl extension for extended internalization support
ipv6 Support IPv6 connectivity in fopen and friends, and v6 address conversions in functions like inet_pton and inet_ntop.
jit Enable PCRE JIT support
ldap-sasl Add SASL support for the PHP LDAP extension using dev-libs/cyrus-sasl
lmdb Enable support for dev-db/lmdb db backend
opcache Enables built-in opcode cache, replacing pecl-apc et al.
opcache-jit Enable Just In Time (JIT) compilation within the opcache extension
pcntl Enable the Process Control extension
pdo Enable the PHP Data Objects extension
phar Enables the phar extension to provide phar archive support
phpdbg Enable the PHP Debug Command Line SAPI (like gdb for php)
session-mm Include dev-libs/mm support for session storage
sharedmem Enable the shmop extension
simplexml Enable the SimpleXML extension
sodium Enable support for crypto through dev-libs/libsodium
sysvipc Enable the PHP System-V semaphore, shared memory and IPC extension
tokenizer Add support for the PHP file parser
tokyocabinet Enable support for dev-db/tokyocabinet db backend
xmlreader Enable the XMLReader extension
xmlwriter Enable the XMLWriter extension
xslt Build the XSL extension

polyml

portable Build the portable interpreter version of Poly/ML instead of native

pypy

ensurepip Install the ensurepip module that uses bundled wheels to bootstrap pip and setuptools (if disabled, it will be only possible to use venv `--without-pip`)
full-stdlib Install complete stdlib as necessary to use PyPy for general purpose programs. By default, only a limited subset that is used when building PyPy3 executables is installed. Note that PyPy2.7's stdlib contains multiple known vulnerabilities.
symlink Install "pypy3" symlink, making this PyPy slot the default PyPy3 implementation that is used for building Gentoo packages.
test-install Install the test suite packages, that are required to run tests in a few reverse dependencies.

python

bluetooth Build Bluetooth protocol support in socket module
ensurepip Install the ensurepip module that uses bundled wheels to bootstrap pip and setuptools (if disabled, it will be only possible to use venv `--without-pip`)
jit Enable experimental Just-In-Time compilation support.
libedit Link readline extension against dev-libs/libedit instead of sys-libs/readline
pgo Optimize the build using Profile Guided Optimization (PGO) by running Python's test suite and collecting statistics based on its performance. This will take longer to build.
valgrind Disable pymalloc when running under dev-debug/valgrind is detected (may incur minor performance penalty even when valgrind is not used)
wininst Install Windows executables required to create an executable installer for MS Windows

python-exec

native-symlinks Install generic symlinks like python and python3. If this flag is disabled, only versioned python3.X executables will be available to end users and ebuilds not using python eclasses.

qu-prolog

pedro Pedro subscription/notification communications system

rakudo

clang Use Clang to compile the MoarVM backend
moar Use the MoarVM as backend

ruby

rdoc Install dev-ruby/rdoc after installing Ruby.
systemtap Enable SystemTap/DTrace tracing

rust

clippy Install clippy, Rust code linter
dist Install dist tarballs (used for bootstrapping)
miri Install miri, an interpreter for Rust's mid-level intermediate representation (requires USE=nightly, sometimes is broken)
nightly Enable nightly (UNSTABLE) features (NOTE: it does not install nightly version, just enables features marked as nightly at time of release)
parallel-compiler Build a multi-threaded rustc (experimental, not tested by upstream)
profiler Build the profiler runtime and rust-demangler tool (needed for '-C profile-generate' or '-C instrument-coverage' codegen opts)
rust-analyzer Install rust-analyzer, A Rust compiler front-end for IDEs (language server)
rust-src Install rust-src, needed by developer tools and for build-std (cross)
rustfmt Install rustfmt, Rust code formatter
system-bootstrap Bootstrap using installed rust compiler
system-llvm Use the system LLVM installation
wasm Build support for the wasm32-unknown-unknown target

rust-bin

clippy Install clippy, Rust code linter
profiler Build the profiler runtime and rust-demangler tool (needed for '-C profile-generate' or '-C instrument-coverage' codegen opts)
rust-analyzer Install rust-analyzer, A Rust compiler front-end for IDEs (language server)
rust-src Install rust-src, needed by developer tools and for build-std (cross)
rustfmt Install rustfmt, Rust code formatter

souffle

ffi Support c++ functors with arbitrary number of arguments
swig Enable SWIG usage, needed for Java and Python bindings

spidermonkey

clang Use Clang compiler instead of GCC
debug Enable assertions to allow for easier debugging of programs that link to spidermonkey -- note this will often crash software on regular end-user systems

swi-prolog

archive Use libarchive for extension packs
cli Add support for CLI interfaces based on readline and libedit
ipc Add support for TIPC inter-process communication
pgo Optimize the build using Profile Guided Optimization (PGO)
yaml Use libyaml for YAML pack

swig

ccache build ccache-swig(a fast compiler cache)

vala

valadoc Installs valadoc documentation generation tool

xsb

mariadb Enable support for the mariadb database backend

yap

R Enable support for connecting R to Prolog
raptor Enable support for Raptor RDF syntax libarary

zig

llvm Build with LLVM backend and extensions enabled.

dev-libs

aml

examples Build and install examples

antlr-c

debugger Compiles debug info into the library

apache-arrow

compute Build the Arrow Compute Modules
dataset Build the Arrow Dataset Modules
json Enables read/write json format
parquet Enables read/write parquet data format
re2 Build with support for regular expressions using the re2 library

appstream

apt Enables Debians APT support

appstream-glib

fonts Enable fonts support for appstream-builder.
stemmer Add word stemming via dev-libs/snowball-stemmer.

apr

old-kernel Enable compatibility with older kernels
urandom Use /dev/urandom instead of /dev/random

apr-util

nss Install apr_crypto_nss module
openssl Install apr_crypto_openssl module

atcore

gui Build test GUI

bitset

tcmalloc Use tcmalloc from dev-util/google-perftools for allocations

boehm-gc

large optimize for large heap size (also increases max root sets)

boost

context Build and install the Boost.Context (and Boost.Fiber) library and all other Boost libraries that depend on it
debug Build and install only the debug version of the Boost libraries. Only enable this flag if you're developing against boost.
doc Install the full API documentation documentation. This takes over 200MB of extra disk space.
nls Build libboost_locale. This library requires compatible C library interfaces, which might not be provided by uClibc or other embedded libraries.
numpy Optionally build NumPy extensions when Boost.Python is enabled
stacktrace Build the full Boost.Stacktrace dynamic library instead of relying on the header-only implementation
tools Build and install the boost tools (bcp, quickbook, inspect, wave)

botan

boost Use dev-libs/boost
tools Install optional tools for e.g. hashing

check

subunit Enable support for the subunit unit test protocol

cyberjack

tools Build and install optional management tools.

cyrus-sasl

authdaemond Add Courier-IMAP authdaemond unix socket support (net-mail/courier-imap, mail-mta/courier)
ldapdb Enable ldapdb plugin
openldap Add ldap support for saslauthd
sample Enable sample client and server
srp Enable SRP authentication
urandom Use /dev/urandom instead of /dev/random

date

only-c-locale Build only the C locale

dbus-c++

ecore Use Ecore integration
glib Use glib integration

eekboard

libcanberra Enable support for media-libs/libcanberra
xtest Enable support for x11-libs/libXtst

efl

bmp Enable WBMP image loader
dds Enable DDS image loader
drm Enable DRM engine
eet Enable Eet image loader
efl-one Combine multiple core libraries into one libefl.so
fribidi Enable bidirectional text support
glib Enable dev-libs/glib support
harfbuzz Enable complex text shaping and layout support
hyphen Enable text hyphenation support
ibus Enable Intelligent Input Bus
ico Enable Ico image loader
json Enable lottie animation support
mono Enable mono bindings
physics Enable Bullet physics effects and support
pmaps Enable PMAPS image loader
psd Enable PSD image loader
scim Enable Smart Common Input Method
system-lz4 Use system liblz4 instead of bundled one
tga Enable Tga image loader
tgv Enable Tgv image loader
tslib Enable x11-libs/tslib for touchscreen events
unwind Enable debug support via sys-libs/libunwind
xcf Enable XCF image loader
xim Enable X Input Method
xpresent Enable x11-libs/libXpresent support

elfutils

debuginfod Enable debuginfod support, both the debuginfod server and the libdebuginfod client library
lzma Support automatic decompression of LZMA-compressed files and kernel images
stacktrace Build experimental eu-stacktrace tool. Relies on integration with dev-util/sysprof. See https://developers.redhat.com/articles/2024/06/11/get-system-wide-profiles-binaries-without-frame-pointers.
utils Install command-line utilities (all the eu-* programs)

fcgi

html Install HTML documentation

folks

telepathy Load contacts from the Telepathy framework
utils Build the folks-inspect utility

fstrm

utils Build fstrm utility programs

gf2x

custom-tune Extra long compile time for tuning hardware specific low-level routines
fft Build an FFT API for multiplication of 2 polynomials over GF(2)

gjs

sysprof Enable profiling data capture support using dev-util/sysprof-capture

glib

dbus Enable dependencies required by glib libraries using dbus service to manage settings saving
elf Enable support for listing and extracting from ELF resource files with gresource tool
introspection Enable generating introspection data (requires dev-libs/gobject-introspection )
mime Pull in shared MIME database that many glib-based applications require at runtime to detect or open files. Warning: do not disable this flag unless installing on a headless server.
sysprof Enable profiling data capture support using dev-util/sysprof-capture
systemtap Build support for profiling and tracing using dev-debug/systemtap
utils Install gtester-report utility to generate test report files for your software; build gresource utility with ELF support.

gmime

smime Enable experimental S/MIME support

gmp

cpudetection Enables runtime CPU detection (useful for binpkgs, compatibility on other CPUs). This only works on amd64/x86 at present. If this flag is enabled, GMP will work on a variety of amd64/x86 CPUs and load accelerated routines for use at runtime depending on the CPU in use. This makes it suitable for binary packages (binpkgs). If this flag is disabled, GMP will be tuned for the CPU being used at build-time and may not be usable on other machines.
pic Force static libraries to be built as PIC to avoid TEXTRELs.

gobject-introspection

doctool Install g-ir-doc-tool for generating documentation from introspected data

hiredict

shim Install header shims for the hiredis api.

imath

large-stack Enables code to take advantage of large stack support

input-pad

eekboard Enable support for dev-libs/eekboard
xtest Enable support for x11-libs/libXtst

intel-compute-runtime

l0 Install the oneAPI Level Zero driver alongside the OpenCL one
vaapi Support the sharing of surfaces with Video Acceleration API (OpenCL Extension #36)

jemalloc

lazy-lock Enable lazy locking (only lock when multi-threaded)
prof Enable allocation profiling
stats Enable statistics calculation/reporting
xmalloc Add support for xmalloc (abort-on-out-of-memory)

json-glib

nls Enable native language support (translations)

ktextaddons

designer Build plugins for dev-qt/designer

libbase58

tools Build command line base58 tool

libbytesize

tools Build bscalc python CLI tool

libcdio

minimal Only build the libcdio library and little more, just to be used to link against from multimedia players. With this USE flag enabled, none of the command-line utilities are built, nor is the CDDA library.

libcec

cubox Enable support for enable support for the TDA995x
exynos Enable support for Exynos chipsets
kernel-cec Enable support for Linux kernel CEC framework
raspberry-pi Enable support for the Raspberry Pi
tools Enable build of cec-client and other test and demo executable tools
udev Enable detection of USB-CEC port by udev
xrandr Enable detection of active HDMI using xrandr extensions

libcgroup

daemon Install the configuration tools and init/config files.
tools Install the cgroup rules processing daemon and init/config files.

libclc

spirv Build SPIRV targets

libdbusmenu

gtk Enable support for GTK+2
gtk3 Enable support for GTK+3

libdex

eventfd Allow use of eventfd
liburing Allow use of liburing (io_uring)sys-libs/liburing
sysprof Enable profiling data capture support using dev-util/sysprof-capture

libevent

clock-gettime Disable use of clock_gettime even if it is available
debug Support for running in debug mode
malloc-replacement Support for replacing the memory management functions
mbedtls Support for net-libs/mbedtls encryption
ssl Support for dev-libs/openssl encryption
verbose-debug Support for verbose debug logging

libffi

exec-static-trampoline Don't rely on dynamic code generation for trampolines.
pax-kernel Use PaX emulated trampolines, for we can't use PROT_EXEC

libffi-compat

pax-kernel Use PaX emulated trampolines, for we can't use PROT_EXEC

libfido2

nfc Enable experimental NFC support

libflatarray

cuda Enables plugins for NVIDIA GPUs (e.g. CUDAAllocator)

libgcrypt

getentropy Use getentropy function to obtain randomness from the kernel

libgdata

crypt Use app-crypt/gcr for keeping tokens and passwords in non-pageable memory for improved security
gnome-online-accounts Enable net-libs/gnome-online-accounts support

libgit2

gssapi Enable GSSAPI support for SPNEGO auth
ssh Enable SSH transport support
trace Enable tracing support

libgit2-glib

ssh Enable SSH transport support

libgpg-error

common-lisp Install common-lisp files

libgpiod

tools Build some useful gpio tools that use libgpiod.

libical

glib Enable dev-libs/glib interface support

libisoburn

external-filters Allow the use of external processes as file content filters (Note: this is a potential security risk)
external-filters-setuid Also allow the use of external setuid processes as file content filters (Note: this is a potential security risk)
frontend-optional Use dev-tcltk/bwidget which is not strictly required for the frontend
launch-frontend Enable the tcl gui for xorriso
launch-frontend-setuid Enable the tcl gui for xorriso under setuid

libisofs

verbose-debug Enable verbose debug messages

libjcat

ed25519 Enable ED25519 verification support via dev-libs/nettle and net-libs/gnutls
gpg Enable GPG verification support via app-crypt/gpgme
pkcs7 Enable PKCS7 verification support via net-libs/gnutls

libjwt

openssl Use openssl libs for crypto functions

liblogging

rfc3195 Enables RFC 3195 protocol (aka syslog-reliable) support. If you don't know what this is, you don't need it!
stdlog Enables liblogging's core component (think of it as a the next version of the syslog(3) API).

libmemcached

hsieh Use Hsieh hash algorithm.
libevent Use the libevent event loop interface.
sasl Use sasl auth for communications.

libmemcached-awesome

libevent Use the libevent event loop interface.
sasl Use sasl auth for communications.

libnfc

pcsc-lite Enable NFC drivers that require pcsc-lite

libnl

python Install experimental dev-lang/python bindings
utils Install command line interface utils

liborcus

spreadsheet-model Enable the spreadsheet model implementation
tools Build various low-level parsers

libowfat

diet Compile against dev-libs/dietlibc

libp11

doc Generate and install API documentation for the package.

libpcre

bzip2 Add support for pcregrep command to search within bzip2-compressed files (via app-arch/bzip2).
pcre16 Build PCRE library for 16 bit characters (e.g. UTF-16).
pcre32 Build PCRE library for 32 bit characters (e.g. UTF-32).
readline Add support for command line editing to pcretest, through sys-libs/readline.
zlib Add support for pcregrep command to search within gzip-compressed files (via sys-libs/zlib).

libpcre2

bzip2 Add support for pcregrep command to search within bzip2-compressed files (via app-arch/bzip2).
pcre16 Build PCRE library for 16 bit characters (e.g. UTF-16).
pcre32 Build PCRE library for 32 bit characters (e.g. UTF-32).
readline Add support for command line editing to pcretest, through sys-libs/readline.
zlib Add support for pcregrep command to search within gzip-compressed files (via sys-libs/zlib).

libpeas

glade Install the glade catalog
python Build support for loading dev-lang/python plugins

libpy

sparsehash Include libpy wrappers for dev-cpp/sparsehash

librdkafka

lz4 Enable support for Kafka's LZ4 compression based on KIP-57 (uses app-arch/lz4)

librelp

gnutls Use GnuTLS
openssl Use OpenSSL

libsecp256k1

ecdh Enable ECDH shared secret computation
ellswift Enable ElligatorSwift encoding for public keys
endomorphism Enable endomorphism
experimental Allow experimental USE flags
extrakeys Enable extrakeys module
lowmem Reduce runtime memory usage at the expense of performance (ecmult window size 4, gen precision 2)
musig Enable MuSig2 module
recovery Enable ECDSA pubkey recovery module
schnorr Enable Schnorr signature module
test-openssl Enable OpenSSL comparison tests

libslz

tools Install additional tools (zenc, zdec)

libsodium

urandom Use /dev/urandom instead of /dev/random

libtermkey

demos Install demos, which pulls in dev-libs/glib

libtomcrypt

libtommath Uses dev-libs/libtommath for mathematical operations
tomsfastmath Uses dev-libs/tomsfastmath for mathematical operations

libucl

regex Enable regex support
sign Enable signatures check
urls Enable URLs fetch
utils Install utils for checking other configs

libunibreak

doc Install html API documentation.

libverto

glib Support event loops using dev-libs/glib
libev Support event loops using dev-libs/libev
libevent Support event loops using dev-libs/libevent

libvoikko

expvfst Enable experimental features of VFST morphology backend
hfst Enable HFST morphology backend

libxlsxwriter

openssl Use dev-libs/openssl for MD5 digest

libxmlb

stemmer Enable language stemming support

libzia

ftdi Enable support for FTDI USB chips

libzip

mbedtls Use net-libs/mbedtls as TLS provider
tools Install binary tools to compare, modify and merge zip files
aspell Adds support for app-text/aspell spell checker
hunspell Adds support for app-text/hunspell spell checker

log4cplus

explicit-initialization Require explicit initialization
iconv Use inconv for wchar_t <-> char conversions. See also log4cplus's unicode.txt documentation
server Build the logging server

log4cxx

smtp Offer SMTP support via net-libs/libesmtp

m17n-lib

X Build the Graphical User Interface API and utilities
anthy Enable support for app-i18n/anthy input method
athena Enable the MIT Athena widget set (x11-libs/libXaw)
gd Build API and utilities based on media-libs/gd. This flag is only meaningful if the X USE flag is also enabled
libotf Use dev-libs/libotf to handle OpenType fonts
libxml2 Use dev-libs/libxml2 to parse XML

mimalloc

hardened Enable exploit mitigations

modsecurity

fuzzyhash Support fuzzy hash computations (to detect malware, for example) using the app-crypt/ssdeep package.
geoip2 Pull in dev-libs/libmaxminddb for use by the SecGeoLookupDb directive.
json Suppose JSON in the request body parser through dev-libs/yajl.
lmdb Add LMDB backend support
pcre2 Use dev-libs/libpcre2 as regex implementation

ncnn

tools Enable installation of various tools in addition to the library

nss

cacert Include root/class3 certs from CAcert (https://www.cacert.org/)
test-full Run all available tests, instead of the standard set only
utils Compile and install all extra binaries, such as certutil, modutil and few more

nwjs

ffmpeg-chromium Use Chromium FFmpeg fork (media-video/ffmpeg-chromium) rather than mainline FFmpeg (media-video/ffmpeg)

oneDNN

cblas Use virtual/cblas for sgemm routines
mkl Use sci-libs/mkl for sgemm routines

onigmo

combination-explosion-check enable combination explosion check
crnl-as-line-terminator enable CR+NL as line terminator

oniguruma

crnl-as-line-terminator Enable CR+NL as line terminator

opencryptoki

tpm Enable support for Trusted Platform Module (TPM) using app-crypt/trousers

openct

debug Add debug output to the driver library for pcsc-lite.
pcsc-lite Build a driver library for sys-apps/pcsc-lite, providing PC/SC API access to devices supported by OpenCT.

openobex

irda Enable IrDA support

opensc

ctapi Use CT-API for accessing Smartcard hardware
notify Enable notifications
openct Use dev-libs/openct (and CT-API) for accessing Smartcard hardware
pace Use dev-libs/openpace for EAC version 2 support
pcsc-lite Use sys-apps/pcsc-lite (and PC/SC API) for accessing Smartcard hardware
secure-messaging Enable secure messaging

openssl

bindist Disable/Restrict EC algorithms (as they seem to be patented) -- note: changes the ABI
fips Enable FIPS provider
ktls Enable support for Kernel implementation of TLS (kTLS)
quic Enable support for QUIC (RFC 9000); a UDP-based protocol intended to replace TCP
rfc3779 Enable support for RFC 3779 (X.509 Extensions for IP Addresses and AS Identifiers)
sslv2 Support for the old/insecure SSLv2 protocol -- note: not required for TLS/https
sslv3 Support for the old/insecure SSLv3 protocol -- note: not required for TLS/https
tls-compression Enable support for discouraged TLS compression
tls-heartbeat Enable the Heartbeat Extension in TLS and DTLS
weak-ssl-ciphers Build support for SSL/TLS ciphers that are considered "weak"

openssl-compat

bindist Disable/Restrict EC algorithms (as they seem to be patented) -- note: changes the ABI
rfc3779 Enable support for RFC 3779 (X.509 Extensions for IP Addresses and AS Identifiers)
sslv2 Support for the old/insecure SSLv2 protocol -- note: not required for TLS/https
sslv3 Support for the old/insecure SSLv3 protocol -- note: not required for TLS/https
tls-compression Enable support for discouraged TLS compression
tls-heartbeat Enable the Heartbeat Extension in TLS and DTLS
weak-ssl-ciphers Build support for SSL/TLS ciphers that are considered "weak"

optix

headers-only Download and install only the header files

pkcs11-helper

nss Enable NSS crypto engine

pocl

accel Enable the generic hardware accelerator device driver
conformance Ensures that certain build options which would result in non-conformant pocl build stay disabled. Note that this does not quarantee a fully conformant build of pocl.
float-conversion When enabled, OpenCL printf() call's f/e/g formatters are handled by pocl. When disabled, these are handled by system C library.
hardening Enable hardening against various attacks. May worsen performance
hwloc Enable hwloc support
memmanager Enables custom memory manager. Except for special circumstances, this should be disabled

poco

7z Add Support for the 7z archive format
activerecord Add ActiveRecord support
cppparser Build and install a minimal C++ parser
data Database abstraction layer to easily send/retrieve data to/from various databases
file2pagecompiler Utility to convert ordinary files to Page Compiler source files
json Add JSON support
jwt Add JSON Web Token support
mariadb Prefer dev-db/mariadb-connector-c over dev-db/mysql-connector-c
mongodb Add dev-db/mongodb support
net Classes to write network clients & servers
pagecompiler Simple compiler translating HTML pages containing embedded C++ code into HTTPRequestHandler classes
pocodoc POCO documentation generator
prometheus Add prometheus monitoring system support
ssl Encryption and digital signing classes
util Several utility classes (like logger, timer, config file parser)
zip Add support for the zip & gz archive formats

ppl

cdd Build the ppl_lcdd program for vertex/facet enumeration accepting the same input format as the programs shipped with sci-libs/cddlib and sci-libs/lrslib
lpsol Build the ppl_lpsol linear program solver that uses sci-mathematics/glpk for its input routines

protobuf

conformance Build conformance tests
libprotoc Build libprotoc
libupb Build libupb
protobuf Build protobuf libraries and protoc compiler
protoc Build libprotoc and protoc compiler

qcoro

network Build dev-qt/qtbase network support
qml Enable QML/QtQuick support via dev-qt/qtdeclarative
websockets Build dev-qt/qtwebsockets support

qcoro5

network Build dev-qt/qtnetwork support
qml Enable QML/QtQuick support via dev-qt/qtdeclarative
testlib Install coroutine-friendly versions of dev-qt/qttest macros
websockets Build dev-qt/qtwebsockets support

qhotkey

qt6 Use Qt6 dependencies

quazip

qt5 Build with Qt5 support
qt6 Build with Qt6 support

raft

zfs ZFS support

re2

benchmark Build a benchmark binary, install it as re2-bench
test-full Run additional, quite slow tests

rocksdb

numa Enable NUMA support
tbb Enable support for dev-cpp/tbb

sentry-native

breakpad Use dev-util/breakpad as the crash handler
curl Enable support for automated uploading of crash reports

serd

tools Build command line utilities

serdisplib

tools Build optional tools.

sexpp

cli Build sexp console application

simdjson

all-impls Enable all implementations rather than only onem
tools Build and install extra command line tools

softhsm

gost Enable gost algorithm
migration-tool Build db migration tool

sord

tools Build command line utilities

starpu

gcc-plugin Enable GCC extension plugin (experimental)
spinlock-check Enable spinlock check

thrift

libevent Build support for dev-libs/libevent

tinyxml

stl Compile with TIXML_USE_STL support

tntnet

server Enable tntnet server daemon

totem-pl-parser

archive Enables ISO detection with app-arch/libarchive
crypt Support AmazonAMZ decoding with dev-libs/libgcrypt
uchardet Enable charset discovery via app-i18n/uchardet

tre

agrep Build agrep tool
alloca Enable if you want TRE to use alloca() instead of malloc() when allocating memory needed for regexec operations
approx Enable the approximate matching functionality

uriparser

unicode Add support for functions working with character type wchar_t (e.g. uriParseSingleUriW with trailing "W") which increases compile time and resulting binary file size by roughly factor 2.

weston

desktop Enable the desktop shell
drm Enable drm compositor support
editor Install wayland-editor example application
fullscreen Enable fullscreen shell
gles2 Enable the GLESv2 renderer, not just the x11-libs/pixman-based software fallback
headless Headless backend and a noop renderer, mainly for testing purposes
ivi Enable the IVI shell
kiosk Enable the kiosk shell
pipewire Enable virtual remote output with Pipewire on DRM backend
rdp Enable Remote Desktop Protocol compositor support
remoting Enable plugin to stream output to remote hosts using media-libs/gstreamer
resize-optimization Increase performance, allocate more RAM. Recommended to disable on Raspberry Pi
screen-sharing Enable screen-sharing through RDP
wayland-compositor Enable Wayland compositor support
xwayland Enable ability support native X11 applications

xerces-c

iconv Use iconv (virtual/libiconv) as message loader and transcoder (in general it would be possible to use iconv only as message loader and something else like icu or the native method as transcoder and vice-versa, but this is a less common case and hard to handle)
threads Enable threading support through pthread (or other libraries on AIX, IRIX, HPUX, Solars). Highly recommended

xmlrpc-c

abyss Build the Abyss mini web-server.
libxml2 Use dev-libs/libxml2 to parse XML instead of the internal expat library.
threads Controls whether to build the Abyss web-server with pthreads or fork 'threading'.

xmlsec

gcrypt Install xmlsec-gcrypt library
gnutls Install xmlsec-gnutls library
http Allow fetching over HTTP via libxml2.
nss Install xmlsec-nss library
openssl Install xmlsec-openssl library

yaz

ziffy Install ziffy, a promiscuous Z39.50 APDU sniffer

dev-lisp

clisp

hyperspec Use local hyperspec instead of online version
svm Build CLISP with support for the Support Vector Machine module

clx

doc Builds documentation

cmucl

doc Installs package documentation
gui Build CLX, CLM, or Hemlock
source Include source code for CMUCL in installation

ecl

gengc Use generational garbage collection (experimental)
precisegc Use type information during garbage collection (experimental)
unicode Make the produced lisp support unicode

gcl

ansi Build a GCL with ANSI support (else build a traditional CLtL1 image)
athena Build xgcl - an interface to x11-libs/libXaw

sbcl

system-bootstrap Bootstrap SBCL using either system SBCL installation or dev-lisp/clisp
unicode Make the produced lisp support unicode

dev-lua

lua-cjson

internal-fpconv Enable internal number conversion routines, can increase overall performance by up to 50%

dev-ml

lablgtk

glade Enable gnome-base/libglade bindings compilation
gnomecanvas Enable gnome-base/libgnomecanvas bindings compilation
sourceview Enable GtkSourceView (x11-libs/gtksourceview) support

logs

cli Enables the Logs_cli library that provides command line support for controlling Logs.
fmt Enables the Logs_fmt reporter.
lwt Enables the Logs_lwt library that provides Lwt logging functions.

ocaml-fileutils

ocamlopt Whether the OCaml native code compiler is used. Must be set globally and match dev-lang/ocaml.

ocaml-gettext

ocamlopt Whether the OCaml native code compiler is used. Must be set globally and match dev-lang/ocaml.

ocaml-gettext-camomile

ocamlopt Whether the OCaml native code compiler is used. Must be set globally and match dev-lang/ocaml.

ocaml-gettext-stub

ocamlopt Whether the OCaml native code compiler is used. Must be set globally and match dev-lang/ocaml.

ocamlnet

httpd Enables net-httpd web server component
zip Enables netzip support to read/write gzip data using object channels

stdlib-shims

ocamlopt Whether the OCaml native code compiler is used. Must be set globally and match dev-lang/ocaml.

tiny_httpd

camlzip Interface to camlzip for tiny_httpd

uutf

utftrip Builds and install the utftrip executable: Among other things, reads unicode on stdin and rewrites it on stdout.

dev-perl

App-Nopaste

browser Spawn browser with pasted page
clipboard copying of URLs with -x/--copy
gitlab Ensure git is installed for reading/passing GitLab authentication
pastebin pastebin.com support

Boulder

genbank Provide support with Boulder::Genbank for decoding Genbank data records
store Provide support with Boulder::Store for persisting Stone objects

Business-ISBN

barcode Install dev-perl/GD-Barcode for rendering ISBN numbers as barcodes

Config-Any

conf Install dev-perl/Config-General to support decoding .conf/.cnf files
ini Install dev-perl/Config-Tiny to support decoding INI config files
json Install support libraries to support decoding JSON config files
xml Install support libraries to support decoding XML config files
yaml Install support libraries to support decoding YAML config files

Cookie-Baker

xs Install dev-perl/Cookie-Baker-XS for accelerated performance

Coro

ev Build support for using dev-perl/EV as an event-loop via Coro::EV
event Build support for using dev-perl/Event as an event-loop via Coro::Event

DBD-MariaDB

mariadb Use dev-db/mariadb-connector-c as the client library
mysql Use dev-db/mysql-connector-c as the client library

DBD-SQLite

system-sqlite Use the system-wide dev-db/sqlite installation

DBD-mysql

mariadb Use dev-db/mariadb-connector-c as the client library
mysql Use dev-db/mysql-connector-c as the client library
ssl Compile in support for SSL connections via libmysqlclient

DBIx-Class

admin Modules required for the DBIx::Class administrative library
admin-script Modules required for the CLI DBIx::Class interface dbicadmin
deploy Modules required for "deploy" in DBIx::Class::Storage::DBI and "deploymen_statements" in DBIx::Class::Storage::DBI
replicated Modules required for DBIx::Class::Storage::DBI::Replicated

File-HomeDir

xdg Ensure XDG Semantics for returned paths via x11-misc/xdg-user-dirs

File-Which

pwhich Install dev-perl/App-pwhich which used to be a part of this package

GD

animgif Enable animated gif support
fcgi Build for FastCGI compatibility via dev-libs/fcgi instead of using PerlIO

HTML-Mason

modperl Enable www-apache/mod_perl support

HTTP-Entity-Parser

xs Install C-Based dependieces for faster performance

JSON

xs Install C-based dev-perl/JSON-XS for faster performance

JSON-MaybeXS

xs Install a C-Based backend to make JSON encode/decode fast

List-MoreUtils

xs Install C-Based backend implementation for performance

MCE

sereal Install dev-perl/Sereal-Encoder and decoder for faster worker IPC

Mail-IMAPClient

md5 Install support for DIGEST-MD5 and CRAM-MD5 Authentication
ntlm Install support for NTLM Authentication
ssl Install support for SSL Connections
zlib Install support for COMPRESS DEFLATE connections

Net-SSH2

gcrypt Use libgcrypt instead of openssl

PDL

badval Enable bad values support
hdf Enable HDF (version 4) format support
netpbm Enable NETPBM and MPEG support
pdl2 Build pdf2 shell (requires Devel-REPL)
pgplot Enable PGPLOT plotting capabilities

Ref-Util

xs Install C-Based dev-perl/Ref-Util-XS for accelerated performance

Sub-Name

suggested Install extra dependencies needed for extended regression tests

Sysadm-Install

hammer Enable hammer() funtion to run a command in the shell and simulate a user hammering the ENTER key to accept defaults on prompts

Test-Warnings

suggested Install optional dependencies for extra tests

Text-CSV

xs Install dev-perl/Text-CSV_XS for accelerated decoding

WWW-Form-UrlEncoded

xs Install C-Based dependieces for faster performance

perl-headers

debug Add source locations in generated .ph files to assist with debugging when errors occur
sizeof-warning Include logic to warn when a .ph file tries to use a sizeof() that is unknown

dev-php

maxmind-db-reader

extension Build the C extension that uses dev-libs/libmaxminddb

pecl-apcu

lock-pthreadmutex Enable pthread mutex locking
lock-pthreadrw Enable pthread read/write locking
lock-semaphore Enable semaphore locks instead of fcntl
lock-spinlock Enable spin locks (EXPERIMENTAL)

pecl-event

extra Add support of the Libevent extra API

pecl-memcached

igbinary Enable support for the igbinary serializer
json Enable support for json serialization

pecl-redis

igbinary Enables igbinary serialisation support
json Enables json serializer support

dev-python

PyQt5

bluetooth Build bindings for the QtBluetooth module
dbus Build bindings for the QtDBus module
declarative Build bindings for the QtQml and QtQuick modules and enable the qmlscene plugin
designer Build bindings for the QtDesigner module and enable the designer plugin
gui Build bindings for the QtGui module
help Build bindings for the QtHelp module
location Build bindings for the QtLocation module
multimedia Build bindings for the QtMultimedia module
network Build bindings for the QtNetwork module
opengl Build bindings for the QtOpenGL module
positioning Build bindings for the QtPositioning module
printsupport Build bindings for the QtPrintSupport module
sensors Build bindings for the QtSensors module
serialport Build bindings for the QtSerialPort module
speech Build bindings for the QtTextToSpeech module
sql Build bindings for the QtSql module
svg Build bindings for the QtSvg module
testlib Build bindings for the QtTest module
webchannel Build bindings for the QtWebChannel module
websockets Build bindings for the QtWebSockets module
widgets Build bindings for the QtWidgets module
x11extras Build bindings for the QtX11Extras module
xmlpatterns Build bindings for the QtXmlPatterns module

PyQt6

bluetooth Build bindings for the QtBluetooth module
dbus Build bindings for the QtDBus module
designer Build bindings for the QtDesigner module and enable the designer plugin
gui Build bindings for the QtGui module
help Build bindings for the QtHelp module
multimedia Build bindings for the QtMultimedia module
network Build bindings for the QtNetwork module
nfc Build bindings for the QtNfc module
opengl Build bindings for the QtOpenGL module
pdfium Build bindings for the QtPdf module (uses pdfium from dev-qt/qtwebengine)
positioning Build bindings for the QtPositioning module
printsupport Build bindings for the QtPrintSupport module
qml Build bindings for the QtQml module and enable the qml plugin
quick Build bindings for the QtQuick module
quick3d Build bindings for the QtQuick3D module
remoteobjects Build bindings for the QtRemoteObjects module
sensors Build bindings for the QtSensors module
serialport Build bindings for the QtSerialPort module
spatialaudio Build bindings for the QtSpatialAudio module
speech Build bindings for the QtTextToSpeech module
sql Build bindings for the QtSql module
svg Build bindings for the QtSvg module
testlib Build bindings for the QtTest module
webchannel Build bindings for the QtWebChannel module
websockets Build bindings for the QtWebSockets module
widgets Build bindings for the QtWidgets module
xml Build bindings for the QtXml module

PyQt6-WebEngine

quick Build bindings for the QtWebEngineQuick module
widgets Build bindings for the QtWebEngineWidgets module

QtPy

designer Pull in bindings for the QtDesigner module and enable the designer plugin
gui Pull in bindings for the QtGui module
help Pull in bindings for the QtHelp module
multimedia Pull in QtMultimedia and QtMultimediaWidgets modules
network Pull in bindings for the QtNetwork module
opengl Pull in bindings for the QtOpenGL module
positioning Pull in bindings for the QtPositioning module
printsupport Pull in bindings for the QtPrintSupport module
pyqt5 Use dev-python/PyQt5 as Qt for Python implementation
pyqt6 Use dev-python/PyQt6 as Qt for Python implementation
pyside2 Use dev-python/pyside2 as Qt for Python implementation
pyside6 Use dev-python/pyside6 as Qt for Python implementation
qml Build bindings for the QtQml
quick Build bindings for the QtQuick
sensors Pull in bindings for the QtSensors module
serialport Pull in bindings for the QtSerialPort module
speech Pull in bindings for the QtTextToSpeech module
sql Pull in bindings for the QtSql module
svg Pull in bindings for the QtSvg module
testlib Pull in bindings for the QtTest module
webchannel Pull in bindings for the QtWebChannel module
webengine Pull in QtWebEngine and QtWebEngineWidgets modules
websockets Pull in bindings for the QtWebSockets module
widgets Pull in bindings for the QtWidgets module
xml Pull in QtXml module

amqp

extras Install extra tools to generate initial Python mod from an AMQP XML file

apprise

dbus Support sending notifications to the desktop over D-Bus
mqtt Support sending notifications over MQTT

autobahn

xbr Add support for XBR decentralized data markets and etherium blockchain

blake3

rust Build the Rust implementation (if disabled, the "experimental" C implementation is used instead).

bpython

clipboard Enable copying to clipboard using dev-python/pyperclip
jedi Enable autocompletion using dev-python/jedi
watch Enable watching paths using dev-python/watchdog

cbor2

native-extensions Compiles native "C" extensions (speedups, instead of using python fallback code).

cvxopt

dsdp Use interior point library sci-libs/dsdp
glpk Use GNU Linear Programming Kit sci-mathematics/glpk

dnspython

dnssec Use dev-python/cryptography to enable low-level DNSSEC RSA, DSA, ECDSA and EdDSA signature validation.

editorconfig

cli Install command line interface as well as python library

fritzconnection

qrcode Install dependencies needed to generate QR Codes for WiFi login.

frozenlist

native-extensions Compile native C extensions (speedups, instead of using Python fallback code).

google-api-core

grpc Pull (heavy) gRPC dependencies in, that are optionally required by part of the API.

httpx

cli Install the CLI "httpx" client.

hypothesis

cli Install a CLI tool used to write tests.

icalendar

doc Generate examples and other extra documentation

immutables

native-extensions Compiles native "C" extensions (speedups, instead of using Python fallback code).

ipython

nbconvert Enable support for converting notebooks to various formats using app-text/pandoc
notebook Install requirements for the web notebook based on dev-python/tornado

markdown-exec

ansi Enable support for rendering ANSI colours in HTML code blocks

matplotlib

excel Pull dev-python/xlwt for the exceltools toolkit
gtk3 Enable x11-libs/gtk+:3 support
webagg Enable webagg backend that uses dev-python/tornado

mido

portmidi Support using media-libs/portmidi as MIDI back-end
rtmidi Support using media-libs/rtmidi as MIDI back-end

mkdocs-material

social Install the dependencies of the "social" plugin.

msgpack

native-extensions Compiles native "C" extensions (speedups, instead of using python fallback code).

multidict

native-extensions Compile native C extensions (speedups, instead of using Python fallback code).

mypy

native-extensions Compiles native C extensions (speedups, instead of using Python fallback code).

netcdf4

blosc Allow using blosc compression via dev-libs/c-blosc

pandas

full-support Pull all packages to give pandas full support

paramiko

server Enable server feature

peewee

native-extensions Compiles native C extension for more complete SQLite3 support.

pillow

imagequant Build with Image Quantization Library support

pivy

quarter Use media-libs/quarter for GUI bindings
soqt Use media-libs/SoQt for GUI bindings

pyarrow

parquet Enables read/write parquet data format

pyglet

image Enable support for image formats other than PNG and BMP

pymongo

native-extensions Compiles native C extensions
test-full Run test suite in full, including tests that run a local database instance.

pyopengl-accelerate

numpy Building NumPy native format handlers.

pypax

ptpax Enable PT_PAX_FLAGS support.
xtpax Enable XATTR_PAX_FLAGS support.

pypy

full-stdlib Install complete stdlib as necessary to use PyPy for general purpose programs. By default, only a limited subset that is used when building PyPy3 executables is installed. Note that PyPy2.7's stdlib contains multiple known vulnerabilities.

pypy-exe

low-memory Build using PyPy with the engine configured towards low memory footprint. This makes it possible to build PyPy using ~3.5G of RAM on amd64 and ~half of that on x86, at the cost of lengthened build time.

pypy3

test-install Install the test suite packages, that are required to run tests in a few reverse dependencies.

pypy3_10

ensurepip Install the ensurepip module that uses bundled wheels to bootstrap pip and setuptools (if disabled, it will be only possible to use venv `--without-pip`)
test-install Install the test suite packages, that are required to run tests in a few reverse dependencies.

pypy3_10-exe

low-memory Build using PyPy with the engine configured towards low memory footprint. This makes it possible to build PyPy using ~3.5G of RAM on amd64 and ~half of that on x86, at the cost of lengthened build time.

pyrsistent

native-extensions Compiles native C extensions (speedups, instead of using python fallback code).

pyside2

3d Build Qt3DCore, Qt3DAnimation, Qt3DExtras, Qt3DInput, Qt3DLogic, and Qt3DRender modules
charts Build QtCharts module
concurrent Build QtConcurrent module
datavis Build QtDataVisualization module
designer Build QtDesigner and QtUiTools modules
gles2-only Build QtGui "QOpenGL*" classes
gui Build QtGui module
help Build QtHelp module
location Build QtLocation module
multimedia Build QtMultimedia and QtMultimediaWidgets modules
network Build QtNetwork module
positioning Build QtPositioning module
printsupport Build QtPrintSupport module
qml Build QtQml module
quick Build QtQuick and QtQuickWidgets modules
scxml Build QtScxml module
sensors Build QtSensors module
speech Build QtTextToSpeech module
sql Build QtSql module
svg Build QtSvg module
testlib Build QtTest module
webchannel Build QtWebChannel module
webengine Build QtWebEngine and QtWebEngineWidgets modules
websockets Build QtWebSockets module
widgets Build QtWidgets module
x11extras Build QtX11Extras module
xml Build QtXml module
xmlpatterns Build QtXmlPatterns module

pyside6

3d Build Qt3DCore, Qt3DAnimation, Qt3DExtras, Qt3DInput, Qt3DLogic, and Qt3DRender modules
bluetooth Build QtBluetooth module
charts Build QtCharts module
concurrent Build QtConcurrent module
designer Build QtDesigner and QtUiTools modules
gles2-only Build QtGui "QOpenGL*" classes
gui Build QtGui module
help Build QtHelp module
location Build QtLocation module
multimedia Build QtMultimedia and QtMultimediaWidgets modules
network Build QtNetwork module
network-auth Build QtNetworkAuth module
nfc Build QtNfc module
pdfium Build QtPdf module
positioning Build QtPositioning module
printsupport Build QtPrintSupport module
qml Build QtQml module
quick Build QtQuick and QtQuickWidgets modules
quick3d Build QtQuick3D and QtQuickWidgets modules
scxml Build QtScxml module
sensors Build QtSensors module
serialport Build QtSerialPort modules
spatialaudio Build QtSpatialAudio module
speech Build QtTextToSpeech module
sql Build QtSql module
svg Build QtSvg module
testlib Build QtTest module
webchannel Build QtWebChannel module
webengine Build QtWebEngine and QtWebEngineWidgets modules
websockets Build QtWebSockets module
widgets Build QtWidgets module
xml Build QtXml module

python-box

native-extensions Compiles native C extensions

python-lsp-server

all-plugins Pull in all optional plugins

python-mpd2

twisted Enable twisted support

python-stdnum

vies Enable VIES

pyudev

qt5 Install PyQt5 bindings

pyzmq

drafts Enable draft API support

qiskit

visualization Enable visualization modules

rarfile

compressed Enables the module to support compressed v3 archives by calling the app-arch/unrar.

reedsolo

native-extensions Compile native C extensions.

rfc3986

idna enable support for the IDNA specification (RFC 5891)

rpyc

gdb Run tests depending on dev-debug/gdb
numpy Run tests depending on dev-python/numpy, dev-python/pandas

shiboken2

docstrings Expose documentation as Python docstrings (recommended)
numpy Implicitly convert passed NumPy arrays to Qt lists
vulkan Generate "QSurface::VulkanSurface" bindings

shiboken6

docstrings Expose documentation as Python docstrings (recommended)
numpy Implicitly convert passed NumPy arrays to Qt lists
vulkan Generate "QSurface::VulkanSurface" bindings

simplejson

native-extensions Compiles native "C" extensions (speedups, instead of using Python fallback code).

stripe

telemetry Enable sending "telemetry to Stripe regarding request latency and feature usage" by default. Upstream enables it by default in their PyPI distribution; it can also be explicitly controlled via stripe.enable_telemetry variable (boolean).

subprocess-tee

test-full Enable full test mode. Pulls in many additional dependencies, and requires having been emerged without this flag first in order to avoid a circular dependency.

sympy

imaging Add support for dev-python/pillow
ipython Add support for dev-python/ipython
mathml Add support for mathml
pyglet Use dev-python/pyglet for plots and print preview
symengine Add support for a dev-python/symengine backend
texmacs Add app-office/texmacs interface

tables

cpudetection Enables runtime CPU detection (useful for bindist, compatibility on other CPUs)

tpm2-pytss

fapi Enable feature API (requires tpm2-tss be compile with thes same)

translate-toolkit

html Support conversion between po and html files
ical Support conversion between po and ical files
ini Support conversion between po and ini files
subtitles Support conversion between po and sub files
yaml Support YAML format

twisted

conch include Twisted SSHv2 implementation
serial include serial port support

websockets

native-extensions Compiles native C extensions

wrapt

native-extensions Compiles native C extensions (speedups, instead of using python fallback code).

zeep

async Add async support

dev-qt

designer

declarative Build the qdeclarativeview plugin

linguist-tools

qml Enable QML support in lupdate

qdoc

qml Enable QML/JS parsing support

qt-creator

clang Build clang-based plugins for C/C++ development (code model, formatting, static analysis)
designer Enable designer for QtWidgets-based UIs
help Enable the integrated dev-qt/qt-docs viewer (also needed for examples)
plugin-dev Install the 'Devel' component needed to build external Qt Creator plugins
qmldesigner Build QmlDesigner and related plugins (Insight, StudioWelcome)
serialterminal Build the serial terminal plugin
tracing Build plugins for tracing requiring extra dependencies (AppStatisticsMonitor, CtfVisualizer, PerfProfiler, QmlProfiler)
webengine Use dev-qt/qtwebengine with the help USE rather than bundled litehtml

qt-docs

3d Install documentation for dev-qt/qt3d
activeqt Install documentation for ActiveQt (unpackaged, Windows-only)
assistant Install documentation for dev-qt/assistant
bluetooth Install documentation for dev-qt/qtbluetooth
charts Install documentation for dev-qt/qtcharts
concurrent Install documentation for dev-qt/qtconcurrent
connectivity Install documentation for dev-qt/qtconnectivity
datavis Install documentation for dev-qt/qtdatavis3d (unpackaged for Qt6)
declarative Install documentation for dev-qt/qtdeclarative
designer Install documentation for dev-qt/designer
gamepad Install documentation for dev-qt/qtgamepad (available in qt overlay only)
graphicaleffects Install documentation for dev-qt/qtgraphicaleffects
graphs Install documentation for QtGraphs (unpackaged)
grpc Install documentation for QtGRPC (unpackaged)
gui Install documentation for dev-qt/qtgui
help Install documentation for dev-qt/qthelp
html Install documentation in HTML format
httpserver Install documentation for QtHTTPServer (unpackaged)
imageformats Install documentation for dev-qt/qtimageformats
linguist Install documentation for dev-qt/linguist
location Install documentation for dev-qt/qtlocation
lottie Install documentation for QtLottie (unpackaged)
multimedia Install documentation for dev-qt/qtmultimedia
network Install documentation for dev-qt/qtnetwork
networkauth Install documentation for dev-qt/qtnetworkauth
positioning Install documentation for dev-qt/qtpositioning
printsupport Install documentation for dev-qt/qtprintsupport
qch Install documentation in QCH format
qdoc Install documentation for dev-qt/qdoc
qt5compat Install documentation for dev-qt/qt5compat
quick3d Install documentation for dev-qt/qtquick3d
quick3dphysics Install documentation for QtQuick3DPhysics (unpackaged)
quickcontrols Install documentation for dev-qt/qtquickcontrols
quickcontrols2 Install documentation for dev-qt/qtquickcontrols2
quickeffectmaker Install documentation for QtQuickEffectMaker (unpackaged)
remoteobjects Install documentation for QtRemoteObjects (unpackaged)
script Install documentation for dev-qt/qtscript
scxml Install documentation for dev-qt/qtscxml
sensors Install documentation for dev-qt/qtsensors
serialbus Install documentation for dev-qt/qtserialbus (unpacakged for Qt6)
serialport Install documentation for dev-qt/qtserialport
shadertools Install documentation for dev-qt/qtshadertools
speech Install documentation for dev-qt/qtspeech
sql Install documentation for dev-qt/qtsql
svg Install documentation for dev-qt/qtsvg
timeline Install documentation for dev-qt/qtquicktimeline
tools Install documentation for dev-qt/qttools
virtualkeyboard Install documentation for dev-qt/qtvirtualkeyboard
wayland Install documentation for dev-qt/qtwayland
webchannel Install documentation for dev-qt/qtwebchannel
webengine Install documentation for dev-qt/qtwebengine
websockets Install documentation for dev-qt/qtwebsockets
webview Install documentation for dev-qt/qtwebview (unpackaged for Qt6)
widgets Install documentation for dev-qt/qtwidgets
x11extras Install documentation for dev-qt/qtx11extras
xmlpatterns Install documentation for dev-qt/qtxmlpatterns

qt3d

gamepad Add support for gamepad hardware via dev-qt/qtgamepad
qml Build QML/QtQuick bindings

qt5compat

qml Build QML/QtQuick bindings and imports

qtbase

X Build the XCB platform plugin and enable X11 integration
concurrent Build Qt6Concurrent module
dbus Build Qt6DBus module
eglfs Build the EGL Full Screen/Single Surface platform plugin
evdev Enable support for input devices via evdev
gssapi Enable support for GSSAPI (virtual/krb5)
gtk Build the GTK platform theme plugin
gui Build Qt6Gui module
journald Log messages using sys-apps/systemd's journald rather than output to stderr (override with the QT_FORCE_STDERR_LOGGING=1 env var)
libinput Enable support for input devices via dev-libs/libinput
libproxy Use net-libs/libproxy for automatic HTTP/SOCKS proxy configuration
network Build Qt6Network module
renderdoc Enable support for capturing graphic's API calls using media-gfx/renderdoc
sql Build Qt6Sql module
syslog Log messages using syslog rather than output to stderr (override with the QT_FORCE_STDERR_LOGGING=1 env var)
tslib Enable support for touchscreen devices via x11-libs/tslib
widgets Build Qt6Widgets module

qtbluetooth

qml Build QML/QtQuick bindings and imports

qtcharts

qml Build QML/QtQuick bindings and imports

qtconnectivity

neard Use net-wireless/neard to access NFC devices
nfc Enable support for the Near Field Communication protocol

qtcore

old-kernel Disable syscalls not available on Linux kernels older than 4.11

qtdatavis3d

qml Build QML/QtQuick bindings and imports

qtdeclarative

localstorage Build the LocalStorage import for QtQuick (requires QtSql)
network Enable QtNetwork support
opengl Enable OpenGL support
qmlls Build the qmlls tool using dev-qt/qtlanguageserver
sql Enable QtSQL support
widgets Enable QtWidgets support

qtdiag

network Report network information
widgets Report widget style information

qtgamepad

evdev Enable support for input devices via evdev
qml Build QML bindings

qtgui

X Build the XCB platform plugin and enable X11 integration
eglfs Build the EGL Full Screen/Single Surface platform plugin
evdev Enable support for input devices via evdev
ibus Build the IBus input method plugin
libinput Enable support for input devices via dev-libs/libinput
linuxfb Enable Linux framebuffer support for embedded devices
tslib Enable support for touchscreen devices via x11-libs/tslib
tuio Build plugin to receive touch events over the TUIO protocol
wayland Provide dev-qt/qtwayland to ensure Qt applications can be run as Wayland clients

qthttpserver

websockets Enable websockets support using dev-qt/qtwebsockets

qtmultimedia

eglfs Enable screen capture support with Qt's EGL Full Screen/Single Surface platform plugin
gstreamer Enable audio support via media-libs/gstreamer
qml Build QML/QtQuick bindings and imports
widgets Build the QtMultimediaWidgets module

qtnetwork

gssapi Enable support for GSSAPI (virtual/krb5)
libproxy Use net-libs/libproxy for automatic HTTP/SOCKS proxy configuration

qtpositioning

geoclue Use enhanced location information from app-misc/geoclue
nmea Build plugin for parsing NMEA (National Marine Electronics Association) sentences
qml Build QML bindings

qtquickcontrols

widgets Enable QtWidgets support

qtquickcontrols2

widgets Enable QtWidgets support

qtremoteobjects

qml Build QML/QtQuick bindings and imports

qtscript

scripttools Build the QtScriptTools module (requires QtWidgets)

qtscxml

qml Build QML/QtQuick bindings and imports

qtsensors

qml Build QML bindings

qtspeech

flite Enable text-to-speech synthesizer plugin using app-accessibility/flite engine
qml Build QML/QtQuick bindings and imports
speechd Enable text-to-speech synthesizer plugin using app-accessibility/speech-dispatcher engine

qttools

assistant Build Qt Assistant and the QtHelp module
clang Enable using libclang for code parsing (linguist/qdoc)
designer Build Qt Designer
distancefieldgenerator Build Qt Distance Field Generator
linguist Build Qt Linguist (GUI requires USE=widgets)
pixeltool Build Qt Pixeltool
qdbus Build the Qt D-Bus Interface (D-Bus Viewer requires USE=widgets)
qdoc Build Qt Documentation Generator
qml Build QML/QtQuick bindings and imports
qmlls Build the QtHelp plugin for the QML language server
qtattributionsscanner Build Qt Source Code Attribution Scanner
qtdiag Build Qt Diag
qtplugininfo Build Qt Plugin Info
widgets Enable QtWidgets support

qtvirtualkeyboard

handwriting Adds handwriting recognition integration support

qtwayland

compositor Enable support for the wayland compositor / server APIs
gnome Build the GNOME-like decoration plugin (loaded by default with GNOME)
qml Build QML/QtQuick bindings and imports
vulkan Enable support for Vulkan-based server buffer integration

qtwebchannel

qml Build QML/QtQuick bindings and imports

qtwebengine

designer Install the QWebEngineView plugin used to add widgets in dev-qt/designer forms that display web pages.
jumbo-build Combine source files to speed up build process.
pdfium Build the QtPdf module based on chromium's PDFium library
qml Build QML/QtQuick bindings and imports
system-icu Use the system-wide dev-libs/icu instead of bundled.
webdriver Build tool for automated testing (ChromeDriver equivalent)
widgets Enable QtWidgets support

qtwebsockets

qml Build QML bindings

qtwidgets

gtk Build the GTK platform theme plugin

qtxmlpatterns

qml Build the XmlListModel import for QtQuick (requires QtDeclarative)

dev-ruby

activesupport

msgpack Support ActiveSupport::MessagePack module

asciidoctor-diagram

barcode Enable diagrams with dev-ruby/rqrcode and dev-ruby/barby
ditaa Enable diagrams with media-gfx/ditaa
lilypond Enable diagrams with media-sound/lilypond
meme Enable diagrams with media-gfx/imagemagick
mscgen Enable diagrams with media-gfx/mscgen
plantuml Enable diagrams with media-gfx/plantuml
tikz Enable diagrams with dev-tex/pgf

barby

cairo Add support for writing images (PNG, PS, EPS and, if supported, PDF and SVG) using dev-ruby/rcairo. Not available on JRuby.
png Add support for writing PNG images using dev-ruby/chunky_png.
prawn Add support for writing PDF documents using dev-ruby/prawn.
qrcode Add support for QRCode 2D codes using dev-ruby/rqrcode.
rmagick Add support for writing images (among others PNG, GIF and JPEG) using dev-ruby/rmagick. Not available on JRuby.

faraday_middleware

mashify Include FaradayMiddleware::Mashify
oauth Include FaradayMiddleware::OAuth
parsexml Include FaradayMiddleware::ParseXml
rashify Include FaradayMiddleware::Rashify

io-event

io-uring Enable io_uring support, and use io_uring instead of epoll

jwt

eddsa Support EdDSA algorithm using dev-ruby/rbnacl

maruku

highlight Enable source code highlighting via dev-ruby/syntax

mysql2

mariadb Use mariadb bindings

net-ssh

chacha20 Use dev-ruby/rbnacl for chacha20-poly1305@openssh.com support
ed25519 Use dev-ruby/ed25519 for Ed25519 support

rrdtool-bindings

graph Enable support for graphing functions

rspec-core

highlight Enable source code highlighting via dev-ruby/coderay

rubygems

server Install support for the rubygems server

vcr

json Add support for casettes serialized with JSON

dev-scheme

bigloo

avahi Enable Avahi support
gpg Enable GPG support
libuv Enable libuv support

gauche-gl

cg Enable NVidia Cg binding

guile

debug-freelist Include garbage collector freelist debugging code
debug-malloc Include malloc debugging code
deprecated Enable deprecated features
discouraged (implied by deprecated) enable merely discouraged features
networking Include networking interfaces
regex Include regular expression interfaces

kawa

awt Assume AWT is available
frontend Build "kawa" front-end program using sys-libs/readline
jemacs Build JEmacs
krl Build BRL emulation and KRL
sax Assume SAX2 is available with dev-java/sax
servlets Build support for generating servlets with Java servletapi
swing Assume Swing is available

mit-scheme

blowfish Compile with blowfish encryption support

racket

chez Build Racket on Chez (Racket CS)
futures Enable racket/future library for fine-grained hardware parallelism
ncurses Add ncurses support for expeditor (REPL expression editor)
places Enable racket/place library for share-nothing parallelism and message-passing communication. Compared to futures, places are heavyweight, but they have a simpler performance model.
threads Enable support for green threads

scm

arrays Support for arrays, uniform-arrays and uniform-vectors.
bignums Support for large precision integers.
cautious SCM will always check the number of arguments to interpreted closures.
dynamic-linking Be able to load compiled files while running.
engineering-notation Floats to display in engineering notation (exponents always multiples of 3) instead of scientific notation.
gsubr generalized c arguments: for arbitrary (more then 11) arguments to C functions.
inexact Support for floating point numbers.
ioext Commonly available I/O extensions: line I/O, file positioning, file delete and rename, and directory functions.
libscm Build and install libscm.a and related headers
macro C level support for hygienic and referentially transparent macros (syntax-rules macros).
regex String regular expression matching.
unix Support for: nice, acct, lstat, readlink, symlink, mknod and sync.

slib

gambit Support for gambit scheme implementation
scm Support for scm scheme implementation

dev-tcltk

expect-lite

debug pull in packages needed for runtime interactive debugger

tcl3d

ode Enable support for physics engine from dev-games/ode
osg Enable support for 3D toolkit from dev-games/openscenegraph

tktreectrl

shellicon shellicon extension

dev-tex

abntex

lyx Install with app-office/lyx layout

biblatex

biber Install the unicode compatible backend processor

pythontex

highlighting Syntax highlighting using dev-python/pygments

dev-texlive

texlive-basic

luajittex Add support for LuaJitTeX: LuaTeX based on LuaJIT which is usually faster.

dev-util

Tensile

client Build and install tensile_client executable to run benchmarks and tune GPU GEMM

babeltrace

elfutils Build the dev-util/lttng-ust debug information filter component class
plugins Build support for Babeltrace 2 Python plugins

bpftool

caps Use sys-libs/libcap to enable unprivileged run support
llvm Use sys-devel/llvm instead of libbfd (sys-libs/binutils-libs) for JIT disassembly

breakpad

tools Build tools

buildbot

docker Add support for worker docker command steps
irc Add support for status delivery through an ircbot.

cargo-audit

fix Add support for 'fix' subcommand (experimental)

catalyst

ccache Enables ccache support
iso Pulls in the depends for building iso images
system-bootloader Pulls in the depends needed to setup livecd bootloader from the host system rather than using a cdtar

ccache

redis Enable Redis backend for storage via dev-libs/hiredis
static-c++ Avoid dynamic dependency on gcc's libstdc++.

cccc

apidoc Build software docs with doxygen/graphviz and metrics with cccc
mfc Add patch for MFC dialect options

codeblocks

contrib Build additional contrib components
fortran Build FortranProject plugin which enables to use Code::Blocks IDE for Fortran language

cppcheck

charts Enable QtCharts usage in the GUI
htmlreport install cppcheck-htmlreport

ctags

json Enable JSON output support
xml Enable XML parsing support
yaml Enable YAML parsing support

cwdiff

mercurial install hg wdiff alias for dev-vcs/mercurial

devhelp

gedit Install plugin for app-editors/gedit

dialog

minimal Disable library, install command-line program only

diffoscope

R Use dev-lang/R
binutils Use sys-devel/binutils
cpio Use app-alternatives/cpio
diff Use sys-apps/diffutils
docx Use app-text/docx2txt
dtc Use sys-apps/dtc
e2fsprogs Use sys-fs/e2fsprogs
file Use sys-apps/file
find Use sys-apps/findutils
gettext Use sys-devel/gettext
gpg Use app-crypt/gnupg
haskell Use dev-lang/ghc
hdf5 Use sci-libs/hdf5
hex Use app-editors/vim-core
iso Use app-cdr/cdrtools
llvm Use sys-devel/llvm
opendocument Use app-text/odt2txt
pascal Use dev-lang/fpc
rpm Use app-arch/rpm
squashfs Use sys-fs/squashfs-tools
ssh Use net-misc/openssh
tar Use app-arch/tar
tcpdump Use net-analyzer/tcpdump
zip Use app-arch/unzip

dropwatch

bfd Add support for Binary File Descriptor

edi

clang Provide integration with sys-devel/clang and dev-util/bear for autocompletion, inline errors and information about compilation units.

flatpak-builder

yaml Use libyaml for yaml support

geany

vte Enable Terminal support (x11-libs/vte)

geany-plugins

ctags Enable ctags plugin
debugger Enable the debugger plugin which interfaces with dev-debug/gdb
enchant Enable spell checking using enchant
gpg Enable geanypg plugin which integrates GPG using app-crypt/gpgme
gtkspell Use gtkspell for dictionary support in GeanyVC
markdown Enable the markdown plugin
pretty-printer Enable pretty-printer plugin
scope Enable the scope plugin which is a graphical GDB front-end
webhelper Enable webhelper plugin
workbench Enable workbench plugin

glade

gjs Build catalog support for dev-libs/gjs widgets.
webkit Build catalog support for net-libs/webkit-gtk:4 widgets.

global

vim Integrate the GNU GLOBAL source code tag system with Vim

gnome-builder

clang Provide integration with sys-devel/clang for best possible C/C++ autocompletion, semantic highlighting, symbol resolving, and diagnostics support
d-spy Provide D-Bus debugging functionality via dev-debug/d-spy
flatpak Enable support for flatpak applications using sys-apps/flatpak
git Provide support for the Git version control system via dev-libs/libgit2-glib (such as setup of Git for New Project, direct cloning for Open Project and changed lines indicators in the editor gutter)
sysprof Provide an integrated profiler via dev-util/sysprof

google-perftools

debug Build a set of libraries with debug support (so-called debugalloc). These are available by default but are not needed unless you're actually developing using tcmalloc.
minimal Only build the tcmalloc_minimal library, ignoring the heap checker and the profilers.
optimisememory To build libtcmalloc with smaller internal caches.
pagesize-128k Use 128K page size for tcmalloc. Larger size makes tcmalloc faster, at the cost of using more space (due to internal fragmentation)
pagesize-16k Use 16K page size for tcmalloc. Larger size makes tcmalloc faster, at the cost of using more space (due to internal fragmentation)
pagesize-256k Use 256K page size for tcmalloc. Larger size makes tcmalloc faster, at the cost of using more space (due to internal fragmentation)
pagesize-32k Use 32K page size for tcmalloc. Larger size makes tcmalloc faster, at the cost of using more space (due to internal fragmentation)
pagesize-64k Use 64K page size for tcmalloc. Larger size makes tcmalloc faster, at the cost of using more space (due to internal fragmentation)

heaptrack

gui Install Qt5-based analyzer tool

hfstospell

clang Use different logic in ebuild when clang is used

hip

hip Build HIP runtime
opencl Build OpenCL runtime
video_cards_amdgpu Build for AMD platform
video_cards_nvidia Build for Nvidia platform

intel-graphics-compiler

vc Enable VectorCompiler for a better performance.

intel-graphics-system-controller

cli Build CLI tools for flashing manually a firmware upgrade.

kcov

binutils Use sys-libs/binutils-libs for `--verify` support

kdevelop

gdbui Enable GUI for attaching GDB to a running process
qmake Enable support for QMake build system
share Enable support for patch sharing using kde-frameworks/purpose

kernelshark

custom-optimization Build with user-specified compiler optimizations (-Os, -O0, -O1, -O2, -O3) from CFLAGS

kup

gitolite Enable support for dev-vcs/gitolite in kup-server

libabigail

btf Handle reading kernel debug files in BTF format via dev-libs/libbpf

librnp

botan Use Botan crypto backend instead of OpenSSL

lttng-tools

ust Support LTTng-UST (Userspace Tracing)

lttng-ust

numa Enable numa support

massif-visualizer

callgraph Enable detailed snapshot analysis using media-gfx/kgraphviewer

mingw64-runtime

default-ucrt Use ucrt instead of msvcrt-os as the default crt (WARNING: incompatible with each others and also for building Wine with USE=mingw, pick one from the start and keep it)
idl Install idl files
libraries Build extra libraries: mangle, pseh, winpthreads
tools Build extra tools: gendef, genidl, widl

mingw64-toolchain

bin-symlinks Symlink executables to usr/bin to be in default PATH (conflicts with crossdev mingw, and crossdev is preferable for a fully featured toolchain)

nvidia-cuda-toolkit

debugger Install the CUDA debugger
nsight Install profiling and optimizing tools (nsight-compute, nsight-systems)
profiler Install the NVIDIA CUDA profiler (nvprof) and the related libraries
rdma Enable infiniband support via sys-cluster/rdma-core
sanitizer Install compute-sanitizer tool
vis-profiler Install the NVIDIA CUDA visual profiler (nvvp)

oprofile

apidoc Provide doxygen generated API docs.

ostree

archive Use libarchive
dracut Install dracut module
gpg Enable GPG support
grub Enable grub configuration generator
httpd Enable ostree trivial-httpd entrypoint
libmount Use libmount
sodium Use libsodium for ed25519
soup Use libsoup for networking

perf

babeltrace Enable dev-util/babeltrace support
bpf Enable support for eBPF features with dev-libs/libbpf
capstone Use dev-libs/capstone for disassembly support
doc Build documentation and man pages. With this USE flag disabled, the --help parameter for perf and its sub-tools will not be available. This is optional because it depends on a few documentation handling tools that are not always welcome on user systems.
libpfm Enable dev-libs/libpfm support
libtraceevent Enable dev-libs/libtraceevent support
libtracefs Enable dev-libs/libtracefs support
numa Enable NUMA support
perl Add support for Perl as a scripting language for perf tools.
systemtap Add support to define SDT event in perf tools.
unwind Use sys-libs/libunwind for frame unwinding support.

pkgconf

native-symlinks Install generic symlinks like pkgconf and pkg-config. If this flag is disabled, only CHOST-prefixed pkg-config executables will be available to end users and ebuilds.

plan9port

freefonts Don't install BigelowHolmes fonts

poke

nbd Enable poking at networked block devices via sys-libs/libnbd.
pvm-profiling Enable profiling in the PVM

pycharm-community

bundled-jdk Use bundled jdk

pycharm-professional

bundled-jdk Use bundled jdk

ropper

z3 Enable Z3 contraint solver support

scanmem

gui Enable the GameConqueror GUI

sccache

azure Enable Azure Blob Storage support
dist-client Enables distributed support in the sccache client
dist-server Enables the sccache-dist binary
gcs Enable Google Cloud Storage support
redis Enable Redis support
s3 Enable full Amazon S3 support
simple-s3 Enable minimal Amazon S3 support

schroot

btrfs Enable support for chroots using btrfs snapshots
dchroot Enables the building of a wrapper named "dchroot", replacing sys-apps/dchroot
lvm Enable support for chroots using LVM snapshots
zfs Enable support for chroots using ZFS shapshots/clones

sdl-jstest

sdl Enable media-libs/libsdl2 based input test
sdl1 Enable media-libs/libsdl based input test

selenium-manager

telemetry Disable sending telemetry by default (avoid-stats config option).

sysprof

unwind Use sys-libs/libunwind to unwind the stack

uftrace

capstone Use capstone to provide dynamic tracing without recompilation

vulkan-tools

cube Build the cube/cubepp demos

watchman

python Install pywatchman bindings and the watchman-{wait,make} utils

dev-vcs

cvs

server Enable server support

darcs

curl Use libcurl for HTTP support.
terminfo Use the terminfo package for enhanced console support.
threaded Use threading and SMP support.

fossil

fusefs Enable the Fuse Filesystem
json Enable the JSON API of Fossil's wiki
system-sqlite Use the system SQLite instead of the bundled one
tcl-private-stubs Enable Tcl integration via private stubs mechanism
tcl-stubs Enable Tcl integration via stubs library mechanism
th1-docs Enable TH1 for embedded documentation pages
th1-hooks Enable TH1 hooks for commands and web pages

git

blksha1 Use the new optimized SHA1 implementation
cgi Install gitweb too
curl Support fetching and pushing (requires webdav too) over http:// and https:// protocols
gpg Pull in gnupg for signing -- without gnupg, attempts at signing will fail at runtime!
highlight GitWeb support for app-text/highlight
mediawiki Support pulling and pushing from MediaWiki
perforce Add support for Perforce version control system (requires manual installation of Perforce client)
safe-directory Respect the safe.directory setting
subversion Include git-svn for dev-vcs/subversion support
tk Include the 'gitk' and 'git gui' tools
webdav Adds support for push'ing to HTTP/HTTPS repositories via DAV

git-annex

assistant Enable git-annex assistant and watch command
benchmark Enable benchmarking
dbus Enable dbus support
gitlfs Build with git-lfs library (rather than vendored copy)
magicmime Use libmagic to determine file MIME types
pairing Enable pairing
torrentparser Use haskell torrent library to parse torrent files
webapp Enable git-annex webapp

git-delete-merged-branches

full-name-executable Install executable /usr/bin/git-delete-merged-branches that is in conflict with dev-vcs/git-extras

gitg

glade Install a glade catalog file
python Install Python bindings for those plugins requiring it.

gitolite

tools Install tools to e.g. convert a Gitosis config to gitolite or one to check if your setup is gitolite >= 3.x compatible

gitolite-gentoo

tools Install tools to e.g. convert a Gitosis config to gitolite or one to check if your setup is gitolite >= 3.x compatible

mercurial

chg Support Mercurial command server client
gpg Support signing with GnuPG.
rust Use Rust extensions.
tk Install dev-lang/tk for hgk script.

subversion

extras Install extra scripts (examples, tools, hooks)
kwallet Enable encrypted storage of passwords with kde-frameworks/kwallet
plaintext-password-storage Enable on-disk caching of plaintext passwords and passphrases. (Enabling this functionality will not force Subversion to store passwords in plaintext, but does permit users to explicitly allow that behavior via runtime configuration.)

games-action

beathazardultra

bundled-libs Use the upstream provided bundled libraries.

descent1-freedata

l10n_de Provides German translations for the game's briefings, robot descriptions, and outro of the original campaign
opl3-musicpack Include alternate version of the game's music, recorded with the Yamaha YMF262 OPL3 soundchip
sc55-musicpack Include alternate version of the game's music, recorded with the Roland Sound Canvas SC-55 MIDI module
textures Include high resolution (640x480) backgrounds, briefing images and fonts (Descent 1)

descent2-freedata

l10n_de Provides German translations for the game's briefings, robot descriptions, and outro of the original campaign
opl3-musicpack Include alternate version of the game's music, recorded with the Yamaha YMF262 OPL3 soundchip
sc55-musicpack Include alternate version of the game's music, recorded with the Roland Sound Canvas SC-55 MIDI module

dxx-rebirth

d1x Install Descent 1 resources and executable
d2x Install Descent 2 resources and executable
data Ensure some game levels are present; if the full game's level data is not already installed then install the playable demo data (i.e. shareware levels)
debug Enable various debugging code paths and sanity checks, not just output. Some of these checks date back to the retail build, and choke on some custom levels because the game was never coded to sufficiently distrust inputs
editor Enable level editor support
l10n_de Provides German translations for the game's briefings, robot descriptions, and outro of the original campaign
midi Enforce that SDL-mixer is used and has midi support
music Enable music support
opl3-musicpack Include alternate version of the game's music, recorded with the Yamaha YMF262 OPL3 soundchip
sc55-musicpack Include alternate version of the game's music, recorded with the Roland Sound Canvas SC-55 MIDI module
sdl2 Use libSDL2, SDL2-mixer instead of libSDL-1* and SDL-mixer-1*
tracker Enable support for the PHP-based multiplayer game tracker

hotline-miami

bundled-libs Use bundled libraries.
launcher Install qt launcher

prismlauncher

qt6 Build with Qt6 support instead of the default Qt5

supermariowar

server Compile and install Super Mario War server files

supertuxkart

nettle Use dev-libs/nettle crypto backend
recorder Enable recording with media-libs/libopenglrecorder
sqlite Record IP bans, statistics in server mode with dev-db/sqlite
wiimote Support for wiimote input devices

swordandsworcery

bundled-libs Use the upstream provided bundled libraries.

trine

launcher Install GTK+ launcher

trine-enchanted-edition

launcher Install GTK+ launcher

trine2

launcher Install GTK+ launcher

games-arcade

bomns

editor enables building the level editor

commandergenius

downloader Allows some Keen games to be downloaded from the menu

jazz2

sdl Prefer SDL2 over GLFW backend
server Build the multiplayer game server

jazz2-data

cc Install The Christmas Chronicles additional data
demo Use the free demo data instead of the full retail game data

lbreakout2

themes Install additional themes

moleinvasion

music Download and install the music files

oshu

osu-skin Include more complete osu-skin (other is minimal)

osu-lazer

pipewire Use pipewire to enable sound output

performous

midi Enable MIDI I/O support
songs Install a few demo songs
webcam Enable Webcam support

tuxanci

physfs Use dev-games/physfs instead of dev-libs/libzip to load compressed data

games-board

cockatrice

client Build with client
oracle Build with oracle
server Compile server support

crafty

no-opts Don't try to enable crazy CFLAG options

freedoko

backgrounds Install additional background images
gnomecards Install the gnome-games card set
kdecards Install the KDE card set
openclipartcards Install the openclipartcards card set
pysolcards Install the PySol card set
xskatcards Install the XSkat card set

pasang-emas

extras Install some extra themes

pioneers

help Enable gnome ingame help via scrollkeeper

pysolfc

extra-cardsets Install extra cardsets
sound Enable sound support using dev-python/pygame

scid

photos Install collection of player photos (large)
scripts Install additional python and tcl utility scripts

stockfish

general-32 Generic unoptimized 32-bits build
general-64 Generic unoptimized 64-bits build
optimize Enable upstream -O3 optimizations (default enabled)

tablebase-syzygy

6-pieces Install tablebases for 6 pieces (huge!)

xboard

default-font Install the default font that xboard uses
zippy Enable experimental zippy client

games-emulation

atari800

encode-mp3 Support recording sound in MP3 format

bsnes-jg

jgmodule Build module for The Jolly Good API
shared Build shared library

desmume

gdb Enable support for the remote GDB stub
openal Use media-libs/openal for microphone input
wifi Enable support for Wi-Fi (experimental and discouraged)

dolphin

discord-presence Enables Discord Rich Presence, show the current game on Discord
evdev Enable evdev input support
llvm Enables LLVM support, for disassembly
log Increase logging output
mgba Enables GBA controllers emulation using libmgba.

dosbox

core-inline Enable memory-increasing inlines for better performance but requiring more build time
glide Enable unofficial Glide emulation via media-libs/openglide

dosbox-staging

dynrec Use recompiling cpu core instead of dynamic x86/x64 specific cpu core
fluidsynth use media-sound/fluidsynth for MIDI emulation
mt-32 use media-libs/munt-mt32emu for MT-32 emulation
network Enable networking features (modem, ipx)
screenshot Enable screenshots of rendered output using media-libs/sdl2-image
slirp Enable Ethernet emulation using net-libs/libslirp

fceux

archive Use app-arch/libarchive for 7zip support
ffmpeg Use media-video/ffmpeg for video recording
x265 Use media-libs/x265 for video recording (HEVC)

gambatte-jg

jgmodule Build module for The Jolly Good API
shared Build shared library

generator

sdlaudio Enable SDL Audio

hatari

capsimage Use dev-libs/spsdeclib to read .IPF, .RAW, and .CTR disk images
capstone Use dev-libs/capstone for disassembly output in the debugger
portmidi Use media-libs/portmidi as an alternative MIDI backend

higan

gtk Use GTK3 (Qt5 if disabled) user interface backend

jgemu

bsnes Install bsnes for Super Nintendo
cega Install Cega for SG-1000, Sega Master System and Game Gear
gambatte Install Gambatte for Game Boy and Game Boy Color
geolith Install Geolith for Neo Geo AES/MVS
jollycv Install JollyCV for ColecoVision
mednafen Install Mednafen for Atari Lynx, Nintendo Virtual Boy, NEC PC Engine, NEC SuperGrafx, Sony PlayStation, Sega Saturn, Super Nintendo, Neo Geo Pocket and WonderSwan
melonds Install MelonDS for Nintendo DS
mgba Install mGBA for Game Boy Advance
nestopia Install Nestopia for Nintendo Entertainment System
prosystem Install ProSystem for Atari 7800
sameboy Install SameBoy for Game Boy and Game Boy Color
vecx Install Vecx for Vectrex

m64py

7z Ensure support for .7z archives.
rar Ensure support for .rar archives.

mgba

discord Enable Discord RPC support
elf Enable the use of elf utils via dev-libs/elfutils
gles3 Build OpenGL ES 3.x RenderSystem
libretro Build libretro port

mupen64plus

audio-sdl Enable SDL audio plugin.
input-sdl Enable SDL input plugin.
rsp-hle Enable HLE RSP plugin.
ui-console Enable default console UI.
ui-m64py Enable PyQt5 UI using games-emulation/m64py.
video-glide64mk2 Enable Glide64mk2 video plugin.
video-rice Enable Rice video plugin.

mupen64plus-core

debugger Build the debugger
netplay Enable netplay functionality
new-dynarec Enable new experimental dynamic recompiler implementation (only for x86 and arm)
opencv Support video capture via media-libs/opencv
osd Overlay emulator messages using on-screen-display

mupen64plus-video-glide64mk2

hires Support hi-resolution textures (requires dev-libs/boost)

pcsx2

clang Use Clang compiler to build (the only compiler that is currently supported by upstream on Linux, do not report bugs if force-disabled)
sndio Enable support for the media-sound/sndio backend

ppsspp

discord Enable interfacing with a locally running Discord desktop client

rmg

angrylion-plugin Enable the mupen64plus-video-angrylion-plus XMAME licensed plugin
discord Enable Discord RPC support
dynarec Enable the new dynarec for the mupen64plus-core plugin
rust-plugin Enable the mupen64plus-input-gca rust plugin

snes9x

libretro Build libretro port
netplay Enable playing ROMs over the network (not recommended)

vbam

link Enable GBA linking functionality

games-engines

devilutionx

sodium Enable network packet encryption using dev-libs/libsodium
zerotier Enable ZeroTier for online public games

exult

fluidsynth Compile with support for FluidSynth
tools Enable tools, usercode compiler and mods support

fheroes2

tools Install development tools like 82m2wav and xmi2midi.

frobtads

tads2compiler Build TADS2 compiler
tads3compiler Build TADS3 compiler

love

gme Use media-libs/game-music-emu to support additional music formats

minetest

client Build Minetest client
leveldb Enable LevelDB backend
prometheus Enable prometheus client support
redis Enable redis backend via dev-libs/hiredis
server Build Minetest server
spatial Enable SpatialIndex AreaStore backend

odamex

client Build client target
hidpi Use bundled FLTK 1.4, which has better support for HiDPI screens
master Build master server target (advertises odamex server list)
odalaunch Build the wxWidgets based launcher
portmidi Enable PortMidi support
server Build server target

openmw

devtools Install development tools like bsatool, esmtool and opencs.
osg-fork Use OpenSceneGraph forked by OpenMW instead of upstream OSG.

scummvm

fluidsynth compile with support for fluidsynth
fribidi Support for right-to-left languages via dev-libs/fribidi
mpeg2 enable mpeg2 codec for cutscenes
net enable cloud support via media-libs/sdl2-net
sndio Enable support for MIDI music using media-sound/sndio
unsupported enable unsupported and/or broken game engines (you're on your own)

scummvm-tools

tremor Enable tremor, a fixed-point version of the Ogg Vorbis decoder

solarus

doc Install doxygen developer documentation.

games-fps

alienarena

vidmode Link against x11-libs/libXxf86vm. Required for full-screen support.

chocolate-doom

midi basic support for MIDI files

darkplaces

cdsound Enables using CD audio in the engine
demo Uses the demo data from quake1 (quake1-demodata)
lights Install and setup the updated light maps
textures Install and setup the updated textures

doomsday

demo Install launcher dor doom1.wad from games-fps/doom-data
display-mode Include the ability to set the display mode
fluidsynth Build the FluidSynth sound driver
freedoom Install launcher for doom1.wad from games-fps/freedoom
tools Build additional tools such as doomsday-shell, md2tool and texc

duke3d-data

demo Extract data files from the shareware version.
gog Extract data files from the GOG.com version.

eduke32

duke3d Install the Duke Nukem 3D data files, provided by games-fps/duke3d-data.
fluidsynth Install media-libs/sdl2-mixer with fluidsynth support.
hrp Install the Duke Nukem 3D High Resolution Pack.
offensive Install the Duke Nukem 3D XXX Pack.
opl Install the Duke Nukem 3D OPL music files.
psx Install the Duke Nukem 3D PSX high resolution voice files.
sc-55 Install the Duke Nukem 3D Roland SC-55 music files.
sdk Install the SDK files.
server Enable support for multiplayer.
tools Install the support tools for mapster32.
voidsw Enable support for Shadow Warrior (Classic) through VoidSW.
voxels Install the Duke Nukem 3D Voxels Pack.
vpx Enable support for media-libs/libvpx.
xmp Enable support for media-libs/exempi.

gzdoom

non-free Enable non-free components
swr Enable software renderer

nexuiz

maps Install the community map pack

prboom-plus

dumb Enable support for various tracker-style music formats via media-libs/dumb
fluidsynth Enable support for MIDI via media-sound/fluidsynth
net Enable support for network play
portmidi Enable support for MIDI via media-libs/portmidi
sdl2-image Enable support for high-resolution texture support via media-libs/sdl2-image
sdl2-mixer Enable support for MIDI via media-libs/sdl2-mixer
server Build PrBoom-Plus server

quake2-icculus

demo Install the demo files (quake2-demodata) and configure for use
qmax Build the pretty version (quake max)
rogue Build support for the 'Ground Zero' Mission Pack (rogue)
xatrix Build support for the 'The Reckoning' Mission Pack (xatrix)

quakeforge

client Build Normal and QuakeWorld clients alongside the servers
wildmidi Use media-sound/wildmidi for midi support

redeclipse

dedicated Install only as a dedicated game server

rott

demo Install the shareware version

sauerbraten

server Compile server support

serioussam

alsa Enable support ALSA sound.
pipewire Enable support for pipewire.
vulkan Enable support Vulkan render.

turtlearena

mumble Adds player-location (positional audio) support to VoIP
server Build server target
voice Adds VoIP support

urbanterror

altgamma Alternative way for gamma setting with modesetting driver
client Build binary for client (includes code for non-dedicated server)
mumble Use Mumble for ingame VoIP (experimental)
server Build binary for dedicated server
skeetshootmod Build support for skeetshoot mod for specific maps
voip Use ioq3 ingame VoIP (experimental)

worldofpadman

maps Install extra maps (PadPack)

xonotic

ode Enable support for physics engine from dev-games/ode

yamagi-quake2

client Build client
ctf Build support for the 'Capture The Flag' addon
gles Build GLES3 renderer
rogue Build support for the 'Ground Zero' Mission Pack
softrender Build software renderer
vulkan Build experimental Vulkan renderer
xatrix Build support for the 'The Reckoning' Mission Pack

games-kids

gcompris

kiosk Enable kiosk mode by default (for use by small children or on a self-service host machine)

games-misc

ponysay

fish-completion Enable fish completion support
non-free Install non-free ponies (i.e. from the MLP franchise)

xcowsay

fortune Enable support for fortune cookies via games-misc/fortune-mod

games-mud

tf

atcp enable ATCP support.
gmcp enable GMCP support.
option102 enable telnet option 102 support.

games-puzzle

gnome-tetravex

cli Build the gnome-tetravex-cli command-line interface
gui Build the gnome-tetravex graphical Gtk user interface

nightsky

bundled-libs Use the upstream provided bundled libraries.

pingus

music Enable playing of background music

tiny-and-big

bundled-libs Use the upstream provided bundled libraries.

world-of-goo-gog

bundled-libs Use bundled libs

world-of-goo-hb

bundled-libs Use bundled libs

games-roguelike

FTL

bundled-libs Use bundled libraries.

angband

sound Enable and install sounds

stone-soup

advpng Use alternate png optimization.
ncurses Enable for console (uses ncurses) based build. (can be enabled on top of tiles)
tiles Enable for graphical (tiled) build. (can be enabled on top of ncurses)

tomenet

client Compile client
server Compile server

games-rpg

daimonin-client

music Install extra music

deponia-doomsday

bonus Install the bonus content (Art Book, Concept Art, Soundtrack)

drascula

sound Install optional audio files

dreamweb

doc High-resolution scans of the written material in the original UK game box

freedroidrpg

devtools Compile the additional dev tools
profile Enable the integration of the ingame real-time profiler

hatoful-boyfriend

gui Install the GUI for configuring screen resolution and input

hatoful-boyfriend-holiday-star

gui Install the GUI for configuring screen resolution and input

kqlives

cheats Enable cheating mode

manaplus

mumble Enable support for voice chat
pugixml Use dev-libs/pugixml for XML parsing isntead of dev-libs/libxml2
sdl2 Use libsdl2 instead of libsdl

the-longest-journey

hd Install high definition backgrounds and sprites
hd-fmv Install upscaled full motion videos

to-the-moon

bundled-libs Use bundled libraries

games-simulation

corsix-th

midi Adds support for background MIDI music via SDL_mixer
tools Build tools for decoding RNC files

flightgear

dbus Enable screensaver DBus interaction
gdal Enable alternative terrain engine based on pagedLOD using sci-libs/gdal
qt5 Build Qt5 launcher application
udev Enable event-based Input devices through virtual/udev
utils Build various utilities (fgpanel, fgviewer among others)

openrct2

scripting Enable the dev-lang/duktape scripting engine for executing user scripts.

openttd

allegro Add support for Allegro
dedicated Build only the openttd server, and not the client.
fluidsynth Compile with support for FluidSynth
lzo Enables LZO compression for savegames. This is only needed to load extremely old savegames. (versions before 0.2)
openmedia Enables the free open media sets: OpenGFX, OpenSFX, OpenMSX, removing the requirement for proprietary TTD assets to play OpenTTD.

simutrans

midi support for background MIDI music via media-sound/fluidsynth
minimal Don't install any PakSets (scenario data)

simutrans-paksets

128 Install higher resolution scenario data (128 px graphics)
comic192 Install comic-like scenario data (192 px graphics)
cs128 Install Czech-Slovak scenario data (128 px graphics)
excentrique48 Install eccentric scenario data (48 px graphics)
german128 Install German scenario data (128 px graphics)
nippon64 Install Nippon scenario data (64 px graphics)

train-valley

gui Install the GUI for configuring screen resolution and input

games-sports

speed-dreams

osggraph Enable the new work-in-progress 3D engine using dev-games/openscenegraph
webstats Enable support for sending racing statistics to a web server (experimental)

xmoto

double-precision more precise calculations at the expense of speed

games-strategy

0ad

editor Include Atlas scenario editor projects
lobby Enable the use of net-libs/gloox and the multiplayer lobby
nvtt Support for some uncompressed data formats (might be needed for some mods)

colobot

devbuild TODO
tools Build tools

colobot-data

music Enable music support

freeciv

gtk3 Build the gtk3 client
gtk4 Build the gtk4 client
json Add support for JSON via dev-libs/jansson
mapimg Additional mag image toolkit via media-gfx/imagemagick
modpack Build the freeciv-modpack-program to download/install mods
rule-editor Build ruleset editor
server Enable server support. Disabling this will also make it impossible to start local games.
sound Add support for sound provided by media-libs/sdl-mixer
system-lua Use dev-lang/lua instead of the bundled liblua
web-server Build the freeciv-web server in place of the freeciv server

freeorion

client Build game client

freesynd

devtools Build development tools

hedgewars

server Enable local server

ja2-stracciatella

editor Adds necessary file to run the editor
ru-gold Support for russian gold ja2 version

megaglest

editor Build map editor
fribidi Enable FriBIDi support
model-viewer Build model viewer
streflop Use the library streflop. Out of synchs may occur if not enabled.
tools Build model import/export tools
unicode Use unicode strings for wxwidgets
wxuniversal Use the wxUniversal port which implements the various GUI controls by drawing them itself

satellite-reign

gui Install the GUI for configuring screen resolution and input

ufoai

client Build the main game client
server Build the dedicated server

uqm

music download and install original 3DO music files
remix download and install remixed music files (large)
voice download and install voice files (large)

wargus

bne Support extracting data from the Battle.net Edition

warzone2100

discord Enable Discord presence/join integration

wesnoth

server Enable compilation of server

games-util

gslist

web Enable the web interface

heroic-bin

gamescope Run Heroic Launcher inside gamescope

lgogdownloader

gui Enable GUI login support for passing reCAPTCHA

sc-controller

trayicon Enable system tray icon

slade

fluidsynth Enable MIDI software synthesis using media-sound/fluidsynth

wit

fuse Enable image mount support via fuse

gnome-base

gdm

bluetooth-sound Allow loading of bluetooth sound modules. This may be necessary for accessibility screen readers, but may cause bluetooth sound issues for users logging in.
fprint Enables experimental fingerprint authentication using sys-auth/fprintd
plymouth Enable support for smooth transition from sys-boot/plymouth

gnome

classic Install gnome-extra/gnome-shell-extensions for the Gnome Shell Classic mode
extras Install additional GNOME applications

gnome-applets

tracker Build the tracker search bar applet

gnome-control-center

gnome-online-accounts Enable configuration panel for net-libs/gnome-online-accounts accounts
ibus Enable support for enhanced input methods through app-i18n/ibus

gnome-extra-apps

games Install Gnome Games
share Install the gnome-extra/gnome-user-share personal file sharing tool
shotwell Install the media-gfx/shotwell photo manager
tracker Install the app-misc/tracker indexer and the GNOME packages that require it

gnome-keyring

ssh-agent Use GNOME Keyring to unlock SSH keys. Recommended unless you are using ECDSA or Ed25519 keys.

gnome-light

gnome-shell Install gnome-base/gnome-shell and x11-wm/mutter for the standard GNOME 3 desktop mode

gnome-session

elogind Support sys-auth/elogind for session tracking

gnome-settings-daemon

elogind Rely on sys-auth/elogind as runtime logind provider
modemmanager Enable WWAN support via net-misc/modemmanager
systemd Rely on sys-apps/systemd as runtime logind provider

gnome-shell

elogind Use sys-auth/elogind for session tracking and suspend support.
ibus Enable support for enhanced input methods through app-i18n/ibus
pipewire Use pipewire to enable the camera monitor

gvfs

afp Enables support for accessing AFP (Apple Filing Protocol) network shares
archive Enables support for accessing files in archives transparently via app-arch/libarchive
bluray Enable playback of Blu-ray filesystems using media-libs/libbluray
elogind Use sys-auth/elogind for session tracking.
fuse Enables fuse mount points in $HOME/.gvfs for legacy application access
gnome-online-accounts Enable configuration panel for net-libs/gnome-online-accounts accounts
google Enables support for accessing Google accounts via dev-libs/libgdata
http Enable the HTTP/DAV backend using net-libs/libsoup
nfs Enable NFS client support via net-fs/libnfs.
udev Enable udev base replacement code for cdda feature

libgnomecanvas

glade Enable glade support

librsvg

tools Build svg viewer tool

nautilus

cloudproviders Enable the cloudproviders support
gstreamer Enable the Audio/Video file properties page
previewer Use gnome-extra/sushi to preview files from the file mananger
sendto Enable the nautilus-sendto extension to send files to various locations/devices

gnome-extra

cinnamon

internal-polkit Use Cinnamon's internal polkit agent instead of gnome-extra/polkit-gnome. This does not currently support multi-user fast switching.

cinnamon-control-center

modemmanager Enable support for mobile broadband devices using net-misc/modemmanager

cjs

sysprof Enable profiling data capture support using dev-util/sysprof-capture

eiciel

nautilus Build gnome-base/nautilus extension

evolution-data-server

berkdb sys-libs/db support needed to migrate old (pre-3.13 evolution versions) addressbook data
gnome-online-accounts Enable net-libs/gnome-online-accounts based Google authentication support
oauth-gtk3 Enable internal OAuth2 authentication for GTK+3 applications (libedataserverui-*.so) support for Google and Outlook.com. If gnome-online-accounts is enabled and used, this is not necessary, but both can be supported at the same time with different setup at runtime
oauth-gtk4 Enable internal OAuth2 authentication for GTK 4 applications (libedataserverui4-*.so) support for Google and Outlook.com. If gnome-online-accounts is enabled and used, this is not necessary, but both can be supported at the same time with different setup at runtime
weather Enable optional weather calendar support

gnome-commander

gsf Add metadata support for OLE, OLE2 and ODF
pdf Add metadata support for PDF
taglib Add metadata support for ID3, Vorbis, FLAC and APE

gnome-contacts

gnome-online-accounts Enable net-libs/gnome-online-accounts based Google authentication support

gnome-network-displays

firewalld Install firewalld zones

gnome-shell-extension-gsconnect

nautilus Install Nautilus extension for sending files via GSConnect

gnome-software

firmware Enable firmware update support through sys-apps/fwupd
flatpak Enable support for flatpak applications using sys-apps/flatpak
snap Enable support for snap packages using app-containers/snapd
sysprof Enable profiling data capture support using dev-util/sysprof-capture

gnome-system-monitor

systemd Display sys-apps/systemd metadata, e.g. unit names, for running processes

libgda

canvas Enable support for x11-libs/goocanvas
http Enable embedded net-libs/libsoup based server
json Enable support for JSON format
mdb Enable support for Microsoft Access database using app-office/mdbtools
sourceview Enable support for x11-libs/gtksourceview

libgsf

gtk Enable use of gdk in thumbnailer

nemo

tracker Add support for app-misc/tracker search

nm-applet

modemmanager Enable support for mobile broadband devices using net-misc/modemmanager
teamd Enable teamd configuration editor

gnustep-apps

gemas

projectcenter Build and install plugin for gnustep-apps/projectcenter

gworkspace

gwmetadata Enable the metadata indexing and searching system

sogo

activesync Build the ActiveSync support code
sodium Enable support for Argon2 password schemes using dev-libs/libsodium

gnustep-base

gnustep-back-art

xim Enable X11 XiM input method

gnustep-back-cairo

xim Enable X11 XiM input method

gnustep-back-xlib

xim Enable X11 XiM input method

gnustep-make

libobjc2 Enables use of the GNUstep Objective-C runtime (gnustep-base/libobjc2) with non-fragile ABI and sys-devel/clang compiler
native-exceptions Enables use of the native Objective-C exception support (@try/@catch/@finally) built-in objective-c exceptions with compilers that support it

gui-apps

foot

grapheme-clustering Enable grapheme clustering support

grim

jpeg Enable JPEG support.

gtkgreet

layershell Enable layer shell support

kanshi

varlink Enable remote control with varlink

mako

icons Enable support for icons

swaybg

gdk-pixbuf Support image types other than PNG

swayidle

elogind Enable support for rootless session via elogind

swaylock

gdk-pixbuf Enable additional image format support via the x11-libs/gdk-pixbuf library

waybar

evdev Enable libevdev support for evdev related features
experimental Enable experimental features, such as Bluetooth battery reporting
libinput Enable libinput support for libinput related features
logind Enable support for logind (bluetooth and idle inhibit)
mpd Enable support for the Music Player Daemon
mpris Enable support for mpris
network Enable libnl support for network related features
pipewire Enable support for pipewire
pulseaudio Enable support for volume control via PulseAudio
sndio Enable support for volume control via sndio
tray Enable support for tray
wifi Enable support for wifi/rfkill

waypipe

dmabuf Use DMABUFs for data exchange and hardware decoding
ffmpeg Link with ffmpeg to allow buffer displays using video streams
systemtap Enable SystemTap/DTrace tracing

wayvnc

gbm enable GPU-side screencopy (experimental)
tracing Trace kernel and memory calls

wf-recorder

pipewire Enable support for audio capture via media-video/pipewire.
pulseaudio Enable support for audio capture via PulseAudio

gui-libs

gtk

broadway Enable the GDK Broadway backend.
cloudproviders Enable GtkPlacesSidebar to access cloud services
colord Use x11-misc/colord for color management in printing
sysprof Enable profiling data capture support using dev-util/sysprof-capture

gtksourceview

sysprof Enable profiling data capture support using dev-util/sysprof-capture

libdecor

dbus Enable dbus to query current cursor theme
examples Build and install examples
gtk Build GTK plugin

libhandy

glade Install module and catalog for dev-util/glade

neatvnc

examples Build and install examples
gbm Enable support for the Generic Buffer Manager (gbm)
h264 Enable H.264 encoding
jpeg Enable JPEG compression
tracing Trace kernel and memory calls
websockets Enable websockets support

vte

icu Enable legacy charset support using dev-libs/icu
systemd Support moving terminal child processes to their own systemd user scopes to avoid terminal getting killed due to child causing OOM

vte-common

systemd Support moving terminal child processes to their own systemd user scopes to avoid terminal getting killed due to child causing OOM

wlroots

X Enable support for X11 applications (XWayland)
drm Enable Direct Rendering Management
libinput Enable support for input devices via dev-libs/libinput
liftoff Enable support for libliftoff KMS plane backend
session Enable session support (is required for DRM and libinput)
x11-backend Enable support for handling input/output devices through x11-libs/libxcb
xcb-errors Better error reporting when using xwayland

xdg-desktop-portal-wlr

elogind Enable support for rootless session via elogind

gui-wm

gamescope

libei Enable emulated input using dev-libs/libei
pipewire Enable screen capture via PipeWire
wsi-layer Enable the WSI layer (required for HDR)

hyprland

legacy-renderer Enable legacy renderer

sway

X Enable support for X11 applications (XWayland)
swaybar Install 'swaybar': sway's status bar component
swaynag Install 'swaynag': shows a message with buttons
tray Enable support for StatusNotifierItem tray specification
wallpapers Install sway's default wallpaper image

wayfire

X Enable support for X11 applications (XWayland).
gles3 Enable OpenGL ES 3.x Features.

kde-apps

akonadi

designer Install plugin for dev-qt/designer
tools Install tools for developers and testing
webengine Enable support for system-wide defined KAccounts

analitza

eigen Enable dev-cpp/eigen mathematical templates support

ark

zip Enable ZIP archive support via dev-libs/libzip

cantor

R Enable dev-lang/R backend support
julia Enable dev-lang/julia backend support
qalculate Enable sci-libs/libqalculate backend support

gwenview

activities Enable kactivities support
fits Enable support for NASA's sci-libs/cfitsio library
mpris Enable support for MPRIS2 interface, requiring dev-qt/qtdbus as dependency.
share Enable support for a share menu using kde-frameworks/purpose

k3b

webengine Use dev-qt/qtwebengine for fancy k3bdiskinfoview

kalarm

pim Enable birthday import, email functions etc. using kde-apps/akonadi

kalzium

editor Enable the embedded molecule editor/viewer
solver Enable the equation solver

kate-addons

filebrowser Enable File System browser tool view
lspclient Enable LSP (Language Server Protocol) client plugin
projects Enable Project plugin for executing queries on SQL DBs
snippets Enable Snippets Tool View plugin to manage or download code snippets
sql Enable SQL plugin for executing queries on SQL DBs

kde-apps-meta

accessibility Pull in kde-apps/kdeaccessibility-meta packages
admin Pull in kde-apps/kdeadmin-meta packages
education Pull in kde-apps/kdeedu-meta packages
games Pull in kde-apps/kdegames-meta packages
graphics Pull in kde-apps/kdegraphics-meta packages
multimedia Pull in kde-apps/kdemultimedia-meta packages
network Pull in kde-apps/kdenetwork-meta packages
pim Pull in KDE PIM suite
sdk Pull in developer-specific meta-packages
utils Pull in kde-apps/kdeutils-meta packages

kdeadmin-meta

cron Installs KDE application for virtual/cron configuration

kdecore-meta

share Install kde-frameworks/purpose for share file context menu actions in kde-apps/dolphin
webengine Enable www-client/falkon which depends on dev-qt/qtwebengine

kdeedu-meta

webengine Enable packages requiring dev-qt/qtwebengine

kdegraphics-meta

color-management Enable color management via media-libs/opencolorio
screencast Pull in kde-apps/spectacle for screenshot/screenrecording support
webengine Enable page scanning support via media-gfx/skanpage

kdemultimedia-meta

cdrom Include packages for optical discs

kdenetwork-meta

bittorrent Pull in net-p2p/ktorrent for BitTorrent protocol support
dropbox Enable support for Dropbox in kde-apps/dolphin via kde-apps/dolphin-plugins-dropbox
samba Enable support for net-fs/samba file sharing plugin from within file properties
screencast Pull in kde-apps/krfb for Plasma desktop sharing support
webengine Enable support for Google Drive integration via kde-misc/kio-gdrive

kdenlive

designer Build plugins for dev-qt/designer

kdepim-addons

importwizard Enable additional import plugins for kde-apps/akonadi-import-wizard
markdown Enable Markdown support via app-text/discount

kdepim-meta

bogofilter Install mail-filter/bogofilter for spam filter support in kde-apps/kmail
clamav Install app-antivirus/clamav for virus detection support in kde-apps/kmail
spamassassin Install mail-filter/spamassassin for spam filter support in kde-apps/kmail

kdesdk-meta

git Enable support for Git VCS in kde-apps/dolphin via kde-apps/dolphin-plugins-git
mercurial Enable support for Mercurial VCS in kde-apps/dolphin via kde-apps/dolphin-plugins-mercurial
subversion Enable support for Apache Subversion VCS in kde-apps/dolphin via kde-apps/dolphin-plugins-subversion
webengine Enable dev-util/kdevelop, requiring dev-qt/qtwebengine

kdeutils-meta

7zip Install app-arch/p7zip for 7zip archive support in kde-apps/ark
gpg Install kde-apps/kgpg which depends on kde-apps/akonadi
lrz Install app-arch/lrzip for LRZ archive support in kde-apps/ark
rar Install one of app-arch/rar, app-arch/unrar or app-arch/unar for RAR archive support in kde-apps/ark
webengine Install app-editors/ghostwriter and kde-apps/kimagemapeditor, requiring dev-qt/qtwebengine

kget

bittorrent Enable bittorrent transfer plugin through net-libs/libktorrent
gpg Enable signature verification by GpgME++ via app-crypt/gpgme
mms Enable MMS (Microsoft Media Server) plugin through media-libs/libmms

kig

geogebra Support files created by sci-mathematics/geogebra-bin
scripting Support Python scripting

kio-extras

X Enable support for XCursor thumbnails via x11-libs/libX11
activities Enable activities KIO worker and fileitem plugin
ios Enable AFC (Apple File Conduit) KIO worker for iOS devices support
kf6compat Disable components colliding with KF6, depend on KF6 components instead
man Enable manpages KIO worker
nfs Enable NFS support using net-libs/libtirpc
phonon Enable file audio preview plugin using media-libs/phonon
sftp Enable SFTP protocol support using net-libs/libssh
taglib Enable audio thumbnails via media-libs/taglib

kleopatra

pim Enable WKS publishing support using kde-apps/kmail

kmag

keyboardfocus Enable keyboard focus tracking

konqueror

activities Enable kactivities support

krdc

activities Enable Plasma Activities support via kde-plasma/plasma-activities

ksystemlog

kdesu Run as root using kdesu from kde-plasma/kde-cli-tools

ktouch

X Enable support for X11 Keyboard Layout Detection

kwave

qtmedia Enable playback via Qt5Multimedia

libkdepim

designer Build plugins for dev-qt/designer

libkgapi

kf6compat Disable components colliding with KF6, depend on KF6 components instead

libksane

kwallet Enable encrypted storage of passwords with kde-frameworks/kwallet

mailcommon

designer Build plugins for dev-qt/designer

marble

aprs Enable support for APRS data sources
designer Install plugin for dev-qt/designer
geolocation Enable position information via dev-qt/qtpositioning
pbf Enable OpenStreetMap PBF file support via dev-libs/protobuf
phonon Enable sound support via media-libs/phonon
shapefile Enable support for ESRI shapefiles
webengine Use dev-qt/qtwebengine for embedded web browser

okular

crypt Enable support for password-encrypted documents via kde-frameworks/kwallet
epub Enable E-Book support via app-text/ebook-tools
markdown Enable Markdown support via app-text/discount
mobi Enable mobipocket support via kde-apps/kdegraphics-mobipocket
phonon Enable sound support via media-libs/phonon
qml Install Okular Qml components
share Enable support for a share menu using kde-frameworks/purpose

parley

webengine Build browser integration for the editor, requires dev-qt/qtwebengine

pimcommon

designer Build plugins for dev-qt/designer

spectacle

share Enable support for a share menu using kde-frameworks/purpose

step

qalculate Enable the libqalculate library for unit conversion

thumbnailers

blender Enable blender thumbnail generation using kde-frameworks/karchive
gettext Enable PO file thumbnail generation using kde-apps/kdesdk-thumbnailers
mobi Enable mobipocket thumbnail generation using kde-apps/kdegraphics-mobipocket
video Enable video thumbnail generation using kde-apps/ffmpegthumbs

yakuake

absolute-position Use kde-plasma/kwayland for absolute window positioning in KWin

kde-frameworks

kcompletion

designer Build plugins for dev-qt/designer

kconfig

qml Enable QML/QtQuick support via dev-qt/qtdeclarative

kconfigwidgets

designer Build plugins for dev-qt/designer

kfilemetadata

epub Enable support for reading EPUB ebook metadata
mobi Enable mobipocket support via kde-apps/kdegraphics-mobipocket

kglobalaccel

kf6compat Disable components colliding with KF6, depend on KF6 components instead

kguiaddons

kf6compat Disable components colliding with KF6, depend on KF6 components instead

kiconthemes

designer Build plugins for dev-qt/designer

kimageformats

eps Support the EPS graphics file format

kinit

caps Capabilities support for improved security and better OOM handling

kio

designer Build plugins for dev-qt/designer
kwallet Enable permanent storage of passwords for kpasswdserver with kde-frameworks/kwallet

kitemmodels

qml Enable QML support via dev-qt/qtdeclarative

kitemviews

designer Build plugins for dev-qt/designer

knewstuff

designer Build plugins for dev-qt/designer
opds Enable support for the Open Publication Distribution System via kde-frameworks/syndication

knotifications

phonon Play notification sounds via media-libs/phonon instead of media-libs/libcanberra
qml Enable QML support via dev-qt/qtdeclarative
speech Enable text-to-speech notification support

knotifyconfig

phonon Play notification sounds via media-libs/phonon instead of media-libs/libcanberra

kplotting

designer Build plugins for dev-qt/designer

ktexteditor

editorconfig Enable support for EditorConfig configuration files

ktextwidgets

designer Build plugins for dev-qt/designer

kwallet

gpg Support wallets with GnuPG encryption in addition to the default blowfish-encrypted file
kf6compat Disable components colliding with KF6, depend on KF6 components instead

kwidgetsaddons

designer Build plugins for dev-qt/designer

kxmlgui

designer Build plugins for dev-qt/designer

networkmanager-qt

teamd Enable Teamd control support

prison

qml Enable QML/QtQuick support via dev-qt/qtdeclarative

purpose

kaccounts Enable support for system-wide defined KAccounts
webengine Enable support for system-wide defined KAccounts

sonnet

aspell Enable the app-text/aspell spell-checking backend
designer Build plugins for dev-qt/designer
hunspell Enable the app-text/hunspell spell-checking backend
qml Enable QML/QtQuick support via dev-qt/qtdeclarative

kde-misc

kdeconnect

X Enable remote input mousepad plugin using x11-libs/libfakekey
pulseaudio Enable system volume control plugin using media-libs/libpulse
telephony Enable telephony plugin using kde-frameworks/modemmanager-qt

kio-gdrive

kf6compat Disable components colliding with KF6, depend on KF6 components instead
share Enable support for a share menu using kde-frameworks/purpose

krename

office Enable support for file naming based on ODF metadata

tellico

bibtex Add support for bibtex importing using btparse from dev-perl/Text-BibTeX
discid Add support for reading disc IDs from audio CDs
yaz Add support for searching Z39.50 databases

kde-plasma

discover

firmware Enable support for firmware upgrades using sys-apps/fwupd
flatpak Enable support for flatpak repositories using sys-apps/flatpak
snap Enable support for snap packages using app-containers/snapd
webengine Enable webflow support using dev-qt/qtwebview and dev-qt/qtwebengine instead of default URL handler

drkonqi

systemd Enable Coredumpd integration

kde-cli-tools

kdesu Build graphical frontend for kde-frameworks/kdesu

kdeplasma-addons

alternate-calendar Support alternate calendar systems (currently Chinese or Indian) via dev-libs/icu
share Enable applet for quickly sharing data to a variety of sources
webengine Enable dictionary and web browser applets using dev-qt/qtwebengine

kinfocenter

usb Show USB device information

ksystemstats

networkmanager Enable improved backend for Network statistics using kde-frameworks/networkmanager-qt

kwin

lock Enable screen locking via kde-plasma/kscreenlocker
screencast Enable screencast portal using media-video/pipewire
shortcuts Enable global shortcuts support via kde-plasma/kglobalacceld

plasma-desktop

ibus Use ibus input method via app-i18n/ibus
scim Enable applets that use app-i18n/scim
webengine Build the OpenDesktop integration plugin

plasma-firewall

firewalld Build net-firewall/firewalld backend
ufw Build net-firewall/ufw backend

plasma-login-sessions

X Install X11 session file for Display Managers (default is Wayland if both enabled)
wayland Install Wayland session file for Display Managers

plasma-meta

browser-integration Enable integration with Chrome/Firefox with browser extensions
colord Enable kde-plasma/kwin color management via x11-misc/colord
crash-handler Pull in kde-plasma/drkonqi for assisted upstream crash reports
crypt Pull in kde-plasma/plasma-vault for encrypted vaults integration
discover Pull in resources management GUI; a centralised GHNS alternative and optional sys-apps/fwupd frontend
display-manager Pull in a graphical display manager
firewall Pull in kde-plasma/plasma-firewall for system firewall administration
flatpak Pull in kde-plasma/flatpak-kcm for flatpak permissions administration
grub Pull in Breeze theme for sys-boot/grub
gtk Enable Breeze widget style and system settings module for GTK+
kwallet Enable support for KWallet auto-unlocking via kde-plasma/kwallet-pam
oxygen-theme Pull in Oxygen icons, sound theme and visual style for KDE Plasma
plymouth Pull in Breeze theme for sys-boot/plymouth
pulseaudio Install Plasma applet for PulseAudio volume management
qt5 Pull in required packages for seamless integration of KF5/Qt5-based applications
sddm Pull in the x11-misc/sddm display manager and system settings module
sdk Pull in kde-plasma/plasma-sdk for Plasma development
smart Pull in kde-plasma/plasma-disks for disk health monitoring
thunderbolt Pull in kde-plasma/plasma-thunderbolt control center module
unsupported Allow packages that are known to ruin runtime experience ** DO NOT FILE BUGS WITH THIS ENABLED **
wacom Pull in kde-plasma/wacomtablet control center module
wallpapers Install wallpapers for the Plasma Workspace
webengine Use kde-apps/khelpcenter to access the locally installed KDE Help System Handbook
xwayland Enable Wayland windows screensharing to XWayland applications via gui-apps/xwaylandvideobridge

plasma-nm

openconnect Build support for the OpenConnect VPN client
teamd Enable Teamd control support

plasma-workspace

appstream Enable AppStream software metadata support
geolocation Enables dataengine providing location information
policykit Enable locale generation and Users KCM using sys-auth/polkit and sys-apps/accountsservice
screencast Enable screencast portal using kde-plasma/kpipewire
telemetry Enable User Feedback control module for kde-plasma/systemsettings
wallpaper-metadata Show metadata for image wallpaper plugin using kde-apps/libkexiv2

powerdevil

brightness-control Enable screen brightness control using app-misc/ddcutil
caps Capabilities support for scheduled wakeup which can wake from suspend (CAP_WAKE_ALARM)

lxqt-base

liblxqt

backlight Enable backlight control features.

lxqt-config

monitor Build monitor settings tool
touchpad Build touchpad settings tool

lxqt-meta

about Install lxqt-base/lxqt-about
admin Install lxqt-base/lxqt-admin
archiver Install app-arch/lxqt-archiver
desktop-portal Enable the LXQt sys-apps/xdg-desktop-portal backend implementation
display-manager Install a graphical display manager
filemanager Install x11-misc/pcmanfm-qt file manager
lximage Install media-gfx/lximage-qt image viewer
minimal Do not install x11-wm/openbox window manager
nls Install dev-qt/qttranslations to better support different locales
powermanagement Install lxqt-base/lxqt-powermanagement package
processviewer Install x11-misc/qps package
screenshot Install x11-misc/screengrab package
sddm Install x11-misc/sddm display manager
ssh-askpass Install lxqt-base/lxqt-openssh-askpass user password prompt tool
sudo Install lxqt-base/lxqt-sudo
terminal Install x11-terms/qterminal package
trash Install gnome-base/gvfs to enable 'trash' functionality in x11-misc/pcmanfm-qt
window-manager Install kde-plasma/kwin window manager

lxqt-panel

colorpicker Build colorpicker plugin
cpuload Build cpuload plugin
desktopswitch Build desktopswitch plugin
directorymenu Build directorymenu plugin
dom Build dom plugin
kbindicator Build kbindicator plugin
mainmenu Build mainmenu plugin
mount Build mount plugin
networkmonitor Build networkmonitor plugin
quicklaunch Build quicklaunch plugin
showdesktop Build showdesktop plugin
spacer Build spacer plugin
statusnotifier Build statusnotifier plugin
sysstat Build sysstat plugin
taskbar Build taskbar plugin
tray Build tray plugin
volume Build volume plugin
worldclock Build worldclock plugin

mail-client

aerc

notmuch Enable support for net-mail/notmuch

alot

doc Install user manual and API documentation

alpine

chappa enhance Alpine by applying Eduardo Chappa's patches
onlyalpine installs only the alpine binary, so it does not collied with pico and/or pine
passfile Adds support for caching passwords into a file between sessions
smime Enable support for S/MIME

balsa

rubrica Adds support for rubrica addressbook
systray Enable System Tray Icon support

claws-mail

archive Enable archiving plugin
bogofilter Build mail-filter/bogofilter plugin
libcanberra Enable sound notification in connection with USE=notification
libnotify Enable notification on the desktop in connection with USE=notification
litehtml Enable dev-libs/gumbo html viewer plugin
notification Notification for new mail in different way, see also USE flags libcanberra, libindicate and libnotify
oauth Enable OAuth2 authentication support
pgp Enable PGP support
python Enable plugin for Python scripting
sieve Build plugin for sieve filter support
smime Build plugin for S/MIME support
spam-report Enable plugin for spam reporting to various services
spamassassin Build mail-filter/spamassassin plugin

evolution

archive Enable archives support in attachments via app-arch/gnome-autoar
bogofilter Build mail-filter/bogofilter plugin
geolocation Enable support for displaying contacts on a map inside evolution using media-libs/libchamplain
highlight Enable text highlighting plugin
ldap Enable support for fetching contacts from an LDAP or Active Directory server using net-nds/openldap
spamassassin Build mail-filter/spamassassin plugin
weather Enable optional weather calendar support
ytnef Enable optional TNEF attachments parser support using net-mail/ytnef

geary

ytnef Enable optional TNEF attachments parser support using net-mail/ytnef

mutt

autocrypt Enable autocrypt.org support
berkdb Enable sys-libs/db database backend for header caching
gdbm Enable sys-libs/gdbm database backend for header caching
gpgme Build gpgme backend to support S/MIME, PGP/MIME and traditional/inline PGP
gsasl Use GNU SASL via virtual/gsasl instead of Cyrus SASL (requires USE=sasl)
hcache Enable header cache, one database backend needs to be enabled
lmdb Enable dev-db/lmdb database backend for header caching
pgp-classic Build classic_pgp backend to support PGP/MIME and traditional/inline PGP
pop Enable support for POP3 mailboxes
smime-classic Build classic_smime backend to support S/MIME
smtp Enable support for direct SMTP delivery
tokyocabinet Enable dev-db/tokyocabinet database backend for header caching

neomutt

asan Enable Address sanitizer for debugging
autocrypt Enable autocrypt.org support
berkdb Enable BDB (Berkley DB) backend for header caching
gdbm Enable GDBM (GNU dbm) backend for header caching
gpgme Build gpgme backend to support S/MIME, PGP/MIME and traditional/inline PGP
kyotocabinet Enable Kyoto Cabinet database backend for header caching
lmdb Enable LMDB (Lightning Memory-Mapped Database) backend for header caching
lz4 Add lz4 support for header cache compression
notmuch Enable support for net-mail/notmuch
pgp-classic Build classic-pgp backend to support PGP/MIME and traditional/inline PGP
qdbm Enable QDBM (Quicker Database Manager) database backend for header caching
smime-classic Build classic-smime backend to support S/MIME
tokyocabinet Enable Tokyo Cabinet database backend for header caching
ubsan Enable undefined behavior sanitizer for debugging
zlib Add zlib support for header cache compression
zstd Add zstd support for header cache compression

roundcube

change-password Allow users to change passwords through Roundcube
enigma Add dependencies to support server-side GnuPG signing and/or encryption through the enigma plugin
fileinfo Use the dev-lang/php fileinfo extension to guess the mime_type of attachments
ldap Add dependencies to support connecting to an LDAP address book server

s-nail

kerberos If network is enabled, this adds support for GSSAPI login on IMAP through virtual/krb5.
net Enable support for network protocols (POP, IMAP and SMTP). If you only need to send mail with the local Transport Agent, disabling this will get you support for only /usr/sbin/sendmail call.
ssl If network is enabled, this adds support for S/MIME and SSL/TLS-powered protocols through dev-libs/openssl.

thunderbird

clang Use Clang compiler instead of GCC
eme-free Disable EME (DRM plugin) capability at build time
hwaccel Force-enable hardware-accelerated rendering (Mozilla bug 594876)
libproxy Enable libproxy support
pgo Add support for profile-guided optimization using gcc-4.5, for faster binaries. This option will double the compile time.
pulseaudio Add sound server support via media-libs/libpulse (may be PulseAudio or Pipewire, or apulse if installed)
rust-extensions Compile and install experimental rust extensions, that may become part of Thunderbird some day.
sndio Enable support for the media-sound/sndio backend
system-av1 Use the system-wide media-libs/dav1d and media-libs/libaom library instead of bundled.
system-harfbuzz Use the system-wide media-libs/harfbuzz and media-gfx/graphite2 instead of bundled.
system-icu Use the system-wide dev-libs/icu instead of bundled.
system-jpeg Use the system-wide media-libs/libjpeg-turbo instead of bundled.
system-libevent Use the system-wide dev-libs/libevent instead of bundled.
system-librnp Use system-wide dev-util/librnp instead of bundled one.
system-libvpx Use the system-wide media-libs/libvpx instead of bundled.
system-png Use the system-wide media-libs/libpng instead of bundled (requires APNG patches)
system-webp Use the system-wide media-libs/libwebp instead of bundled.
wifi Enable necko-wifi for NetworkManager integration, and access point MAC address scanning for better precision with opt-in geolocation services

mail-filter

MailScanner

exim Set mail-mta/exim to used MTA
postfix Set mail-mta/postfix to used MTA
spamassassin Enable usage of mail-filter/spamassassin for spam protection

amavisd-new

courier Add courier support
dkim Add DomainKeys Identified Mail support
qmail Add qmail support
razor Add support for mail-filter/razor
rspamd Add support for mail-filter/rspamd extension (HTTP only)
rspamd-https Add support for mail-filter/rspamd extension (both HTTP and HTTPS)
spamassassin Add support for mail-filter/spamassassin

bogofilter

tokyocabinet Enable Tokyo Cabinet database support

dcc

rrdtool Enable net-analyzer/rrdtool interface scripts

libmilter

poll Use poll instead of select

maildrop

authlib Add courier-authlib support
dovecot Add dovecot authentication support
tools Install maildirmake and deliverquota tools
trashquota Count deleted messages as part of the maildir quota

mimedefang

poll Use poll instead of select

opendkim

ldap Enable openldap as a dataset facilitator or keys, determining domains to sign for, and any other dataset that opendkim supports.
lmdb Add support for using dev-db/lmdb
lua Enables control over signature verification, filtering and policy to be controlled by user defined lua scripts.
memcached Add support for using dev-libs/libmemcached
opendbx Use opendbx backend to facilitate dataset driven OpenDKIM configuration options like stats, bodylengthdb, etc. against a wide variety of database types
poll Use poll() instead of select() for the provided asynchronous resolver library.
querycache Add support for query caching (requires 'berkdb' flag)
sasl Used to authenticate to a LDAP server in various ways if required.
stats Add support for statistics (requires 'opendbx' flag)
unbound Use the unbound dnssec library to perform DKIM DNS queries.

opendmarc

reports Install the reports binaries: expire, import, reports, params
spf Use the mail-filter/libspf2 for Sender Policy Framework checking

pyzor

gdbm Enables the Gdbm back-end database engine for pyzord
mysql Enables the MySQL back-end database engine for pyzord through dev-python/mysqlclient.
pyzord Enable the pyzord server daemon
redis Enables the redis back-end database engine for pyzord through dev-python/redis

rspamd

hyperscan Enable hyperscan for fast regexp processing
jit Enable PCRE JIT support

spamassassin

cron Install a cron job to update SpamAssassin's rules daily.
qmail Build qmail functionality and docs

mail-mta

courier

fax Enables fax support in the courier mail server
norewrite Prevents courier mail server from mangling virtual user addresses when sending
web Enable the web interface
webmail Enable the webmail interface

exim

arc Adds support for Authenticated Receive Chain (ARC)
dane Adds support for DNS-based Authentication of Named Entities
dcc Adds support for Distributed Checksum Clearinghouse (DCC)
dkim Adds support for DomainKeys Identified Mail (DKIM)
dlfunc Install local_scan.h header to compile separate dlfunc libraries
dmarc Adds support for DMARC
dnsdb Adds support for a DNS search for a record whose domain name is the supplied query
dovecot-sasl Adds support for Dovecot's authentication
dsn Adds support for Delivery Status Notifications (DSN)
lmtp Adds support for lmtp
mbx Adds support for UW's mbx format
pkcs11 Require pkcs11 support in net-libs/gnutls with USE=gnutls
prdr Adds support for Per-Recipient Data Response
proxy Add support for being behind a proxy, such as HAProxy
redis Adds support for querying dev-db/redis
spf Adds support for Sender Policy Framework
srs Adds support for Sender Rewriting Scheme
tdb Use sys-libs/tdb for internal database storage (such as hints database)
tpda Adds support for Transport Post-Delivery Actions

msmtp

daemon Build/install msmtpd MTA daemon
mta Enable this to install as system-wide MTA

netqmail

gencertdaily Generate SSL certificates daily instead of hourly
highvolume Prepare netqmail for high volume servers
pop3 Include POP3 server

notqmail

gencertdaily Generate SSL certificates daily instead of hourly
highvolume Prepare notqmail for high volume servers
pop3 Include POP3 server

opensmtpd

mta Enable this to install as system-wide MTA

postfix

dovecot-sasl Enable net-mail/dovecot protocol version 1 (server only) SASL implementation
eai Add support for SMTPUTF8
ldap-bind Add support for binding to LDAP backend using dev-libs/cyrus-sasl
lmdb Add support for using dev-db/lmdb for lookup tables
memcached Add support for using net-misc/memcached for lookup tables
mongodb Add support for using dev-db/mongodb for lookup tables

qpsmtpd

postfix create user with permissions for proper postfix interaction

ssmtp

mta Install symlinks for sendmail-compatible MTA.

mate-base

caja

mate Install x11-themes/mate-icon-theme which is needed when this package is used in the MATE desktop environment.

mate

base Install base MATE Desktop applications that are recommended for the most common usage; for example, this installs the file manager. Disable this and other USE flags if you want a more minimal MATE Desktop.
extras Install additional MATE Desktop applications that are recommended for extended usage of the MATE Desktop as upstream sees it; for example, this installs MATE Desktop's office related applications. Disable this if you plan to use your own non-MATE Desktop alternatives or a custom mixture of MATE and non-MATE packages.
help Install gnome-extra/yelp to handle in application help menus and documentation browsing
notification Force notification daemon to default to MATE's notification daemon. Enabled by default. Disable if it causes conflicts with other installed desktop environments.
themes Install MATE Desktop's themes; if you use other themes, you can disable this to spare some space and time.

mate-applets

cpupower Enable support for cpu frequency manipulation using sys-power/cpupower
netlink Use dev-libs/libnl

mate-applets-meta

appindicator Pull in mate-extra/mate-indicator-applet for AppIndicator applet
sensors Pull in mate-extra/mate-sensors-applet for hw sensors applet

mate-control-center

accountsservice Add support for AccountsService

mate-session-manager

gles2 Build with support for GLESv2 acceleration sessions

mate-settings-daemon

rfkill build support for rfkill

mate-extra

caja-extensions

cdr Add an extension to burn files to cds using app-cdr/brasero.
gajim Add an extension to support net-im/gajim.
image-converter Add image conversion support.
mail Add an extension to support e-mail functionality.
media Add video audio extension with totem.
open-terminal Add an extension to support an open terminal.
pidgin Add an extension to support net-im/pidgin
share Add an extension to support sharing files.
wallpaper Add an extension to support setting an image as the current wallpaper

mate-polkit

accountsservice Support extraction of data from AccountsService

mate-power-manager

applet Enable building of the MATE applet.

mate-system-monitor

wnck Enable experimental support using x11-libs/libwnck.

mate-tweak

dropdown Support the x11-terms/tilda dropdown terminal emulator

mate-utils

applet Enable the mate dictionary applet

media-fonts

corefonts

tahoma Also install the Tahoma font. Due to the lack of a free bold variant, this may render badly. See bug 184790.

culmus

ancient Install ancient semitic scripts
fancy Install fancy fonts
fontforge Use media-gfx/fontforge to build fonts from source
taamey Install taamey fonts

dejavu

fontforge Use media-gfx/fontforge to build fonts from source

fonts-meta

emoji Install a font supporting emojis
latin Install additional latin fonts
ms Install (free) fonts for the "ms" preset

intlfonts

bdf Install BDF fonts in addition to PCF

iosevka

iosevka Install the classic Iosevka font.
iosevka-aile Install Iosevka Aile, a quasi-proportional sans-serif font.
iosevka-curly Install Iosevka Curly, a curlier variant of Iosevka.
iosevka-curly-slab Install Iosevka Curly Slab, the curly font, with slab-serifs.
iosevka-etoile Install Iosevka Etoile, a quasi-proportional slab-serif font.
iosevka-slab Install Iosevka Slab, a monospace slab-serif font.
iosevka-ss01 Install Iosevka SS01, an Iosevka variant made in the style of Andale Mono.
iosevka-ss02 Install Iosevka SS02, an Iosevka variant made in the style of Anonymous Pro Style.
iosevka-ss03 Install Iosevka SS03, an Iosevka variant made in the style of Consolas.
iosevka-ss04 Install Iosevka SS04, an Iosevka variant made in the style of Menlo.
iosevka-ss05 Install Iosevka SS05, an Iosevka variant made in the style of Fira Mono.
iosevka-ss06 Install Iosevka SS06, an Iosevka variant made in the style of Liberation Mono.
iosevka-ss07 Install Iosevka SS07, an Iosevka variant made in the style of Monaco.
iosevka-ss08 Install Iosevka SS08, an Iosevka variant made in the style of Pragmata Pro.
iosevka-ss09 Install Iosevka SS09, an Iosevka variant made in the style of Source Code Pro.
iosevka-ss10 Install Iosevka SS10, an Iosevka variant made in the style of Envy Code R.
iosevka-ss11 Install Iosevka SS11, an Iosevka variant made in the style of X Windows Fixed.
iosevka-ss12 Install Iosevka SS12, an Iosevka variant made in the style of Ubuntu Mono.
iosevka-ss13 Install Iosevka SS13, an Iosevka variant made in the style of Lucida.
iosevka-ss14 Install Iosevka SS14, an Iosevka variant made in the style of JetBrains Mono.
iosevka-ss15 Install Iosevka SS15, an Iosevka variant made in the style of IBM Plex Mono.
iosevka-ss16 Install Iosevka SS16, an Iosevka variant made in the style of PT Mono.
iosevka-ss17 Install Iosevka SS17, an Iosevka variant made in the style of Recursive Mono.
iosevka-ss18 Install Iosevka SS18, an Iosevka variant made in the style of Input Mono.

liberation-fonts

fontforge Use media-gfx/fontforge to build fonts from source

montecarlo

bdf Install BDF fonts in addition to PCF

mplus-outline-fonts

ipafont Generates new fonts merged with media-fonts/ja-ipafonts

noto

extra Install full upstream font set including condensed, semi-bold, extra-light variants

noto-emoji

icons Install Noto Emoji icon theme

terminus-font

a-like-o Changes view of letter 'a' - a looks like o (see homepage)
center-tilde Place the '~' character vertically centered on the line instead of to the top.
distinct-l ll2 variant with more distinctive l (lowercase L)
otf Install Open Type Font (OTF) (required for HarfBuzz backend)
pcf-8bit Install Portable Compiled Font (PCF) (X11 bitmap fonts), 8-bit encodings
pcf-unicode Install Portable Compiled Font (PCF) (X11 bitmap fonts), Unicode encodings
psf Install PC Screen Font (PSF) with unicode data (for linux console)
quote Changes view of quotes: symmetric ` and ' instead of asymmetric one (see homepage)
ru-dv Changes view of Russian letters 'de' and 've' (see homepage)
ru-g Changes view of Russian letter 'ge' (see homepage)
ru-i Changes view of Russian letter 'i' - not like Latin u, but like "mirrored" N (see homepage)
ru-k Changes view of Russian letter 'k' (see homepage)

unifont

fontforge Use media-gfx/fontforge to build fonts from source
utils Install unifont utilities

media-gfx

ahoviewer

plugins Build plugin support for now, in future pull additional plugins
rar Rar archive support
zip Zip archive support

album

plugins Install optional plugins
themes Install optional themes

alembic

hdf5 Add support sci-libs/hdf5
test Build and run the test-suite

asymptote

boehm-gc Enables using the Boehm-Demers-Weiser conservative garbage collector
context Enables support for ConTeXt format (dev-texlive/texlive-context)
curl Enables running remote programs via net-misc/curl
lsp Enables Language Server Protocol
offscreen Enables off-screen rendering
sigsegv Enables using dev-libs/libsigsegv

blender

alembic Add support for Alembic through media-gfx/alembic.
bullet Enable Bullet (Physics Engine).
collada Add support for Collada interchange format through media-libs/opencollada.
color-management Enable color management via media-libs/opencolorio.
cuda Build cycles renderer with nVidia CUDA support.
cycles Build cycles renderer (requires media-libs/openimageio and dev-libs/boost).
cycles-bin-kernels Precompile the cycles render kernels for the CUDA/HIP/OneAPI backends, if they are enabled, at compile time. This makes it so that the user doesn't have to wait for the kernels to compile when they are used for the first time in Blender. If this option is not on, they will be built as needed at runtime.
dds Adds DDS textures support to Blender.
embree Use embree to accelerate certain areas of the Cycles render engine.
experimental Build Experimental Blender Modules
fluid Adds fluid simulation support via the built-in Mantaflow library.
headless Build without graphical support (renderfarm, server mode only).
hip Build cycles renderer with AMD HIP support.
nanovdb Enable nanoVDB support in Cycles. Uses less memory than regular openVDB when rendering.
ndof Enable NDOF input devices (SpaceNavigator and friends).
oidn Enable OpenImageDenoiser Support
oneapi Build OIDN with Intel oneAPI SyCL support
openimageio Enable OpenImageIO Support
openpgl Enable path guiding support in Cycles
opensubdiv Add rendering support form OpenSubdiv from Dreamworks Animation through media-libs/opensubdiv.
openvdb Enable openvdb for volumetric processing, like the voxel remesher. Also enables volumetric GPU preview rendering for Nvidia cards.
optix Add support for NVIDIA's OptiX Raytracing Engine.
osl Add support for OpenShadingLanguage scripting.
potrace Add support for converting bitmaps into Grease pencil line using the potrace library.
pugixml Enable PugiXML support (Used for OpenImageIO, Grease Pencil SVG export)
renderdoc Build Blender with renderdoc support
tbb Use threading building blocks library from dev-cpp/tbb.
vulkan Add support for the experimental Vulkan viewport backend

chafa

tools Build command-line tools

darktable

gamepad Support using game controllers as input devices
geolocation Enable geotagging support
kwallet Enable encrypted storage of passwords with kde-frameworks/kwallet
lto Enable link-time optimisations in the RawSpeed library
midi Support using MIDI input devices such as Behringer X-Touch Mini, Arturia Beatstep or Korg nanoKONTROL2, as input devices
tools Install tools for generating base curves and noise profiles

digikam

addressbook Enable akonadi contact integration
imagemagick Enable support for additional image formats such as XCF, FITS, HEIC etc.
lensfun Enable support for media-libs/lensfun
panorama Build the panorama plugin which requires media-gfx/hugin
semantic-desktop Enable kde-frameworks/kfilemetadata support
video Enable integrated video player

eog-plugins

map Enable world map display using media-libs/libchamplain

eom

imagemagick Use media-gfx/imagemagick as an external backend for the thumbnailer

exact-image

swig Adds Swig support dev-lang/swig

exiv2

bmff Add support for the ISOBMFF format
webready Support reading metadata over the internet

fbida

X Install the Motif based image viewer "ida"
fbcon Install the framebuffer image viewer "fbi"
ghostscript Install the framebuffer ghostscript viewer "fbgs"

fig2dev

ghostscript Require app-text/ghostscript-gpl to export PDF an bitmap formats

fontforge

truetype-debugger Enable truetype debugger in fontforge
woff2 Enable support for WOFF2 format

fotowall

webcam Enable webcam support

freecad

addonmgr Build the addon manager module for automatic handling of 3rd party addons
cloud Build the Cloud workbench, to access cloud providers (mostly Amazon S3).
designer Build and install the Qt designer plugin, so the FreeCAD widgets can be used from within designer.
fem Build the FEM module and workbench which provides Finite Element Analysis (FEA) workflows
gui Build FreeCAD with a Qt based GUI. If built without setting this USE flag, FreeCAD can be used in a headless mode, for server-side instances. The Python modules are available, without their GUI parts though, if this is unset.
idf Build the IDF module to provide file exchange capabilities with IDF files
image Build the image module and workbench for working with bitmap images
inspection Build the inspection workbench which gives you specific tools for examination of shapes (experimental)
material Build the material module and workbench to work with materials
netgen Build support for the netgen mesher through media-gfx/netgen.
openscad Build the OpenSCAD module for interoperability with OpenSCAD and repairing Constructive Solid Geometry (CSG) history
part-design Build the part design module and workbench for build part shapes from sketches
path Build the path module and workbench to procude G-Code instructions for CNC
pcl Use external sci-libs/pcl for point clouds support.
points Build the points module and workbench for working with point clouds
raytracing Build the raytracing module and workbench for raytracing and rendering
robot Build the robot module and workbench for studying robot movements
show Build the show module, a helper module for visibility automation
smesh Build the Salome SMESH module
surface Build the surface module and workbench
techdraw Build the techdraw module and workbench, a more advanced and feature-rich successor of the drawing workbench
tux Build the Tux module

geeqie

ffmpegthumbnailer Enable video thumbnail support with media-video/ffmpegthumbnailer
map Enable items GPS map display

gimp

fits Enable support for loading/exporting FITS images
vector-icons Enable support for vector icons (experimental)

graphicsmagick

dynamic-loading Compile graphicsmagick with dynamically loadable modules
fpx Enable FlashPix support with media-libs/libfpx
q16 Set storage quantum size to 16 (~2*memory)
q32 Set storage quantum size to 32 (~5*memory)
zip Build with dev-libs/libzip to support the OpenRaster (ORA) format.

graphviz

X Builds unflatten, vimdot, builds plugin -Txlib, and enables support for x11 in various other modules (needs cairo)
devil Enables DevIL output plugin -Tdevil
gtk2 Enables gtk+ output plugin -Tgtk (needs cairo)
gts Enables support for GNU Triangulated Surface Library (required for sfdp to work)
lasi Enables PostScript output via media-libs/lasi, for plugin -Tlasi (needs cairo)

gthumb

slideshow Enable slideshow plugin

hugin

sift automatically align images with media-gfx/autopano-sift-C

imagemagick

corefonts Use media-fonts/corefonts which is required by some commands
fpx Enable media-libs/libfpx support
hdri Enable High Dynamic Range Images formats
lqr Enable experimental liquid rescale support using media-libs/liblqr
pango Enable Pango support using x11-libs/pango
q32 Set quantum depth value to 32
q8 Set quantum depth value to 8

imv

freeimage Use media-libs/freeimage for additional image support

inkscape

cdr Enable support for CorelDRAW files via media-libs/libcdr
dia Enable DIA flow chart import via app-office/dia
inkjar Enable support for OpenOffice.org SVG jar files
sourceview Enable syntax highlighting support via x11-libs/gtksourceview
svg2 Enable support for new SVG2 features
visio Enable support for Microsoft Visio diagrams via media-libs/libvisio
wpg Enable support for WordPerfect graphics via app-text/libwpg

iscan-plugin-gt-f500

minimal Install the firmware only, and not the plugin.

kphotoalbum

map Enable map display support using kde-apps/marble
phonon Enable media-libs/phonon video backend (known to crash on some video formats)
share Enable support for a share menu using kde-frameworks/purpose
vlc Enable media-video/vlc video backend (recommended for X11)

krita

color-management Enable color management via media-libs/opencolorio
media Enable sound support for animations via media-libs/mlt
mypaint-brush-engine Enable MyPaint brush engine support media-libs/libmypaint
qtmedia Enable sound support for animations via dev-qt/qtmultimedia
xsimd Enable usage of SIMD instructions via dev-cpp/xsimd

librecad

tools Build additional tool programs: tff2lff

luminance-hdr

fits Enable support for the FITS format

mandelbulber

opencl Enable GPU rendering support using OpenCL

meshlab

double-precision Use double type instead of float type for scalars

netgen

logging Enable logging through dev-libs/spdlog
opencascade Enable OpenCASCADE support

nomacs

opencv Build support for media-libs/opencv
plugins Build officially support plugins

okularpart

epub Enable E-Book support via app-text/ebook-tools
mobi Enable mobipocket support via kde-apps/kdegraphics-mobipocket

openclipart

gzip Compresses clip art using gzip

openscad

egl Build using EGL instead of GLX
experimental Enable experimental features
gamepad Add support for gamepads through dev-qt/qtgamepad
gui Enable or disable building of the GUI
hidapi Build in support for HID-Class devices using dev-libs/hidapi
mimalloc Build using dev-libs/mimalloc as memory allocator
spacenav Add support for space navigator devices through dev-libs/libspnav

openvdb

abi10-compat Disables newer features to maintain compatibility with ABI10
abi11-compat Disables newer features to maintain compatibility with ABI11
abi12-compat Disables newer features to maintain compatibility with ABI12
abi8-compat Disables newer features to maintain compatibility with ABI8
abi9-compat Disables newer features to maintain compatibility with ABI9
alembic Add support for Alembic through media-gfx/alembic.
ax Build the OpenVDB AX module to perform custom manipulation of OpenVDB data via an expression language: AX
blosc Allow using blosc compression via dev-libs/c-blosc
cuda Enable support for CUDA in NanoVDB
nanovdb A lightweight, header only, and GPU friendly version of VDB
numpy Build pyopenvdb with support for dev-python/numpy
utils Build utility binaries

photoqt

devil Support additional image formats using media-libs/devil
freeimage Support additional image formats using media-libs/freeimage
mpv Support for video files using media-video/mpv

plantuml

ant-task Provides classes used to manage PlantUML Ant task

potrace

metric default to a4 paper size and metric measurement

povray

io-restrictions POV-Ray's mechanism for control of I/O operations

pqiv

archive Enable support for images in archives and cbX comic book files

pstoedit

emf Enable media-libs/libemf support
pptx Enable support for generating PowerPoint pptx files

qimgv

opencv Enable HQ scaling via media-libs/opencv
video Add support for gif/webm playback via libmpv

qrencode

png Enable PNG output support in qrencode tool

renderdoc

qt5 Build and install the qrenderdoc GUI

shotwell

opencv Enable face detection via media-libs/opencv

skanpage

ocr Enable support for Optical Character Recognition via app-text/tesseract

solvespace

system-mimalloc Use system dev-libs/mimalloc instead of vendored library

ueberzugpp

opencv Use media-libs/opencv for additional image formats and OpenCL accelerated scaling
wayland Enable wayland support (proper window positioning is only supported with some compositors)
xcb-errors Use x11-libs/xcb-util-errors for better error reporting with X

xpaint

pgf Support for loading PGF images

yafaray

fastmath Enable mathematic approximations to make code faster
fasttrig Enable trigonometric approximations to make code faster
opencv Add support for media-libs/opencv image processing.

media-libs

a52dec

djbfft Prefer D.J. Bernstein's library for fourier transforms

allegro

dumb Enable media-libs/dumb module library support
physfs Enable physfs support
vga Enables the VGA graphics driver

alsa-lib

alisp Enable support for ALISP (ALSA LISP) interpreter for advanced features.

alure

dumb Enable media-libs/dumb module library support
fluidsynth Enables Fluidsynth MIDI software synthesis

assimp

collada Add support for Collada interchange format through media-libs/opencollada
samples Build viewer library

aubio

double-precision Compile in double precision mode.

avidemux-core

system-ffmpeg Use the ffmpeg provided by the system.

avidemux-plugins

aften Enable A/52 (AC-3) audio encoder support.
amr Enable Adaptive Multi-Rate format support via media-libs/opencore-amr.
dcaenc Enable DTS Coherent Acoustics audio encoder support via media-sound/dcaenc.
fdk Adds support for encoding AAC using media-libs/fdk-aac.
fribidi Enable unicode bidirectional algorithm support via dev-libs/fribidi.
twolame Enable TwoLAME support via media-sound/twolame, an optimised MPEG Audio Layer 2 (MP2) encoder.
vpx Enable WebM VP8 Codec SDK support via media-libs/libvpx.
x265 Enables HEVC support with media-libs/x265.

cal3d

16bit-indices Enables use of 16bit indices

chromaprint

tools Build and install fpcalc and fpcollect tools

clutter

gtk Use gdk-pixbuf from x11-libs/gtk+ as image rendering backend

cogl

kms Enable KMS support.
pango Build cogl-pango library for x11-libs/pango integration

coin

exceptions Compile with C++ exceptions
qch Install API documentation in QCH format
qthelp Build API documentation in QtHelp format

cubeb

sndio Enable support for the media-sound/sndio backend

dav1d

10bit Add support for building 10-bit and 12-bit AV1.
8bit Add support for decoding 8-bit AV1.
xxhash Enable dev-libs/xxhash support for hashing muxer

devil

allegro Add support for Allegro

dumb

allegro Add support for Allegro 4

embree

compact-polys Enables double indexed poly layout.
ispc Build Embree with support for ISPC applications.
raymask Enables ray mask support.
ssp When enabled, Embree compiles with stack protection against return address overrides. Stack protection will wield a minor performance decrease in return for higher security.
tbb Use TBB instead of the built-in Embree tasking system.
tutorial Enable to build Embree tutorials programs.

esdl

image Enable image support

fcft

harfbuzz Use media-libs/harfbuzz for grapheme and run shaping
libutf8proc Use media-libs/harfbuzz and dev-libs/libutf8proc for run shaping

flickcurl

raptor Use media-libs/raptor for proper RDF serializing

freetype

adobe-cff Use Adobe CFF as default font-renderer
bzip2 Support bzip2 compressed PCF fonts.
cleartype-hinting Bytecode hinting mode for TrueType fonts that activates subpixel hinting (a.k.a. ClearType hinting) by default
fontforge Install internal headers required for TrueType debugger in media-gfx/fontforge (built with USE=truetype-debugger)
harfbuzz Use media-libs/harfbuzz for auto-hinting OpenType fonts. WARNING: may trigger circular dependencies!
infinality Enable infinality options for improved LCD filtering
utils Install utilities and examples from ft2demos

freeverb3

forcefpu Disable assembly code
plugdouble Build plugins in double precision mode (default is float)

ganv

fdgl Use experimental force-directed graph layout

gegl

lensfun Enable support for media-libs/lensfun.
sdl2 Add support for Simple Direct Layer 2.0 (media-libs/libsdl2)
umfpack Enable sparse solving via sci-libs/umfpack.

glew

egl-only Enable EGL support and disable X11 support

glfw

wayland-only Enable wayland support and disable X11 support

gmmlib

custom-cflags Do not override user CFLAGS like -march, -msse and similar with lib defaults. Not tested by upstream.

grilo

playlist Enable support for playlists through dev-libs/totem-pl-parser

gst-plugins-bad

bzip2 Enable bzip2 encoder/decoder plugin

gst-plugins-base

X Enable ximagesink and xvimagesink plugins; build GLX platform support if USE=opengl is enabled; build x11 windowing system support if USE=egl is enabled
gbm Enable Graphics Buffer Manager based EGL windowing system support (requires egl and at least one of gles or opengl)
gles2 Enable OpenGL library and plugin via GLESv2 API (requires egl)
ivorbis Enable integer based vorbis decoder
opengl Enable OpenGL library and plugin via desktop OpenGL API
pango Enable pango GStreamer plugin
wayland Enable Wayland EGL windowing system support (requires egl and at least one of gles2 or opengl)

gstreamer

unwind Enable sys-libs/libunwind usage for better backtrace support in leaks tracer module

harfbuzz

experimental Enable experimental APIs
glib Enable dev-libs/glib unicode functions
graphite Enable media-gfx/graphite2 complementary shaper

imlib2

X Use the X window system
apidoc Provide doxygen generated API docs
bzip2 Bzip2 loader support
eps Eps image loader support
filters Build filter functions (blur, sharpen, etc)
heif Heif and Avif image loader support
mp3 ID3 loader support
packing Enable structure packing. This will reduce memory footprint at the cost of unaligned memory access
shm Use MIT shared memory support for X image transfer
text Build text (TrueType font) functions
zlib Zlib loader support

intel-mediasdk

tools Build analyse and inspect tools

jasper

heif Enable experimental support for HEIF/HEIC, unsupported by upstream

leptonica

utils Install command-line utilities

lib3mf

system-act Use system-provided dev-go/act as code generator instead of package provided binaries. This flag will be removed after some time used for testing!

libafterimage

shaping Use MIT shaped X windows extention.
shm Use MIT shared memory extention for X image transfer.

libao

sndio Add support for media-sound/sndio

libass

libunibreak Use dev-libs/libunibreak for Unicode line breaking algorithm

libavif

aom Enable support for the AOM codec encoding and decoding
dav1d Enable support for the dav1d codec decoding
extras Build extra apps (avifenc, avifdec) and test files
gdk-pixbuf Build a gdk-pixbuf loader
rav1e Enable support for the rav1e codec encoding
svt-av1 Enable support for the SVT-AV1 encoder

libbdplus

aacs Add support for decryption of AACS

libbluray

aacs Add support for decryption of AACS
bdplus Use media-libs/libbdplus for BD+ decryption
java Add support for BD-J
utils Install command-line utilities and examples

libcanberra

alsa Enables ALSA sound driver.
gstreamer Enables gstreamer sound driver. Not useful when alsa or pulseaudio is available.
gtk2 Enables building of gtk+ helper library, gtk+ runtime sound effects and the canberra-gtk-play utility. To enable the gtk+ sound effects add canberra-gtk-module to the colon separated list of modules in the GTK_MODULES environment variable.
gtk3 Enables building of gtk+3 helper library, gtk+3 runtime sound effects and the canberra-gtk-play utility. To enable the gtk+3 sound effects add canberra-gtk-module to the colon separated list of modules in the GTK_MODULES environment variable.
pulseaudio Enables PulseAudio sound driver that should be able to support positional event sounds. This is the preferred choice for best sound events experience and picked by default if compiled in and possible to use at runtime.
sound Install x11-themes/sound-theme-freedesktop to get sounds on Gnome and Xfce.
tdb Enables Trivial Database support for caching purposes.

libde265

dec265 Enable build of dec265 example program
enc265 Enable build of enc265 tool
sdl Enable video output of dec265 example program with media-libs/libsdl
tools Enable installation of varous binary tools

libffado

test-programs Install standalone test programs

libggi

3dfx Enables support for Voodoo chipsets, also called 3DFX and TDFX
vis Enables sparc vis support for libggi

libgphoto2

serial Enable serial port support

libgpod

gtk Enable ArtworkDB support

libheif

aom Use media-libs/libaom for AVIF encoding/decoding
gdk-pixbuf Enable x11-libs/gdk-pixbuf plugin
go Enable building dev-lang/go code/examples
rav1e Use media-video/rav1e for AVIF encoding
svt-av1 Use media-libs/svt-av1 for SVT-AV1 encoding
x265 Use media-libs/x265 for HEIF encoding

libjxl

gdk-pixbuf Build a gdk-pixbuf loader.
jpeg Enable full support for JPEG images. When disabled, only lossless conversion between JPEG and JPEG-XL is supported.

liblastfm

fingerprint Build the lastfm-fingerprint library

libmp4v2

utils Install command-line utilities

libmypaint

gegl Add support for media-libs/gegl

libopenglrecorder

openh264 Enable H.264 support using media-libs/openh264
vpx Enable VP8/VP9 codec support via media-libs/libvpx

libpagemaker

tools Build command line file format conversion tools

libpano13

suitesparse Use Sparse Levenberg Marquardt algorithm instead of dense Levenberg Marquardt algorithm

libplacebo

glslang Use dev-util/glslang to compile GLSL
lcms Add support for color management via media-libs/lcms
libdovi Use media-libs/libdovi to read Dolby Vision metadata
shaderc Use media-libs/shaderc to compile GLSL
xxhash Use dev-libs/xxhash to speed up internal hashing

libpng

apng support unofficial APNG (Animated PNG) spec

libprojectm

gles2 Provide support for OpenGL ES 2 and 3

libpulse

asyncns Use libasyncns for asynchronous name resolution.
doc Build the doxygen-described API documentation.
glib Add support to dev-libs/glib-based mainloop for the libpulse client library, to allow using libpulse on glib-based programs.

libsdl

joystick Control joystick support (disable at your own risk)
sound Control audio support (disable at your own risk)
tslib Build with tslib support for touchscreen devices
video Control video support (disable at your own risk)

libsdl2

fcitx Enable support for app-i18n/fcitx
gles1 include OpenGL ES 1.0 support
haptic Enable the haptic (force feedback) subsystem
ibus Enable support for app-i18n/ibus
joystick Control joystick support (disable at your own risk)
kms Build the KMSDRM video driver
pipewire Enable support for the media-video/pipewire audio backend
sndio Enable support for the media-sound/sndio backend
sound Control audio support (disable at your own risk)
video Control video support (disable at your own risk)

libshumate

sysprof Enable sysprof-capture support for profiling

libtgvoip

dsp Enable signal processing (echo cancellation, noise suppression, and automatic gain control)

libv4l

bpf Enable support for IR BPF decoders
tracer Build the v4l2-tracer tool and library
utils Build the v4l-utils collection of utilities

libva-compat

drm Enables VA/DRM API support.

libva-intel-driver

hybrid Enable support for hybrid vaapi hardware acceleration on Intel Haswell and newer architectures

libva-intel-media-driver

redistributable Install redistributable media kernel binaries (no source code) files (primarily needed for video encoding support)

libvisio

tools Build conversion tools

libvmaf

embed-models Compile default vmaf models into the library (needs app-editors/vim-core)

libvpl-tools

drm Build with DRM support

libvpx

highbitdepth Enable 10 and 12 bit support for VP9.
postproc Enable additional post processing filters

libwebp

swap-16bit-csp Enable byte swapping for 16 bit colorspace

libzmf

tools Build conversion tools

lilv

tools Build command line utilities

lsp-plugins

lv2 Build lv2 plugins
vst Support LinuxVST plugins

lv2

plugins Enables examples plugins.

lvtk

gtk2 Enable x11-libs/gtk+:2 based GUI support
tools Compile and install ttl2c tool

mesa

d3d9 Enable Direct 3D9 API through Nine state tracker. Can be used together with patched wine.
llvm Enable LLVM backend for Gallium3D.
lm-sensors Enable Gallium HUD lm-sensors support.
opencl Enable the Rusticl Gallium OpenCL state tracker.
osmesa Build the Mesa library for off-screen rendering.
proprietary-codecs Enable codecs for patent-encumbered audio and video formats.
vdpau Enable the VDPAU acceleration interface for the Gallium3D Video Layer.
vulkan-overlay Build vulkan-overlay-layer which displays Frames Per Second and other statistics
wayland Enable support for dev-libs/wayland
xa Enable the XA (X Acceleration) API for Gallium3D.

mesa-amber

gles1 Enable GLESv1 support.
wayland Enable support for dev-libs/wayland

mlt

frei0r Build the module for media-plugins/frei0r-plugins
opencv Build motion tracking module using media-libs/opencv
python Build SWIG bindings for Python
rtaudio Builds rtaudio consumer for native audio support on multiple platforms
rubberband Enable audio pitch-shifting using media-libs/rubberband
vidstab Enabled video stabilization with media-libs/vidstab

netpbm

rle Build converters for the RLE format (utah raster toolkit)

noise-suppression-for-voice

lv2 Enable the LV2 plugin
vst Enable the VST plugin
vst3 Enable the VST3 plugin

oidn

apps Build the standalone denoise, self test, and benchmark binaries.
hip Build OIDN with AMD HIP support.
openimageio Enable OpenImageIO Support

oneVPL-cpu

openh264 Use media-libs/openh264 instead of media-libs/x264

openal

pipewire Enable support for the media-video/pipewire audio backend
sndio Enable support for the media-sound/sndio backend

opencolorio

apps Build the OCIO command line apps

opencv

atlas Use sci-libs/atlas for blas, lapack and sparse blas routines
contrib Install user contributed scripts from opencv_contrib (Experimental!)
contribcvv Enable CVV in contrib (requires Qt5)
contribdnn Enable DNN module contrib (requires tinydnn)
contribfreetype Enable Drawing UTF-8 strings with media-libs/freetype&media-libs/harfbuzz
contribhdf Enable HDF module (requires sci-libs/hdf5)
contribovis Enable OGRE vision module support (dev-games/ogre)
contribsfm Enable SFM module (requires USE="eigen gflags glog")
contribxfeatures2d Enable xfeatures2d in contrib
cuda Enable NVIDIA Cuda computations support (Experimental!)
cudnn Enable support for nVidia cuDNN library
dnnsamples Enable dnn caffeemodel samples
eigen Enable usage of dev-cpp/eigen for computations
features2d Enable features2d module
gdal Enable support for sci-libs/gdal library
gflags Use Google's C++ argument parsing library (dev-cpp/gflags)
glog Use Google's C++ logging library (dev-cpp/glog)
gtk3 Enable x11-libs/gtk+:3 support
jasper Use media-libs/jasper for jpeg2k support
mkl Use sci-libs/mkl for blas, lapack and sparse blas routines
non-free Enable non-free components
opencvapps Enable compilation with opencvapps
quirc Enable qrcode decoding via media-libs/quirc
tbb Enable multithreading with the Intel Threads Building Block (dev-cpp/tbb)
tesseract Use Google's OCR Engine
testprograms Build and install programs for testing OpenCV (performance)
truetype Enable media-libs/freetype support for gapi module
video_cards_intel Enable Video Acceleration API for hardware decoding for Intel cards
vtk Build new 3D visualization module viz based on sci-libs/vtk

openexr

large-stack Enables code to take advantage of large stack support.
utils Build several binary tools for verifying and manipulating EXR files.

openh264

plugin Install the Gecko Media Plugin (GMP) for use with Mozilla packages
utils Install the CLI encoder and decoder utilities

openimageio

dicom Enable DICOM medical image file support via sci-libs/dcmtk
fits Enable support for NASA's sci-libs/cfitsio library
gui Build iv (with Qt5)
opencv Enable OpenCV support via media-libs/opencv
openvdb Enable OpenVDB support via media-gfx/openvdb
ptex Enable Ptex texture mapping system file support via media-libs/ptex
qt6 Build iv with Qt6
tools Build the command-line tools

opensubdiv

glew Enable support for OpenGL Extension Wrangler Library (media-libs/glew)
glfw Build all example files that uses (media-libs/glfw)
ptex Adds support for faster per-face texture mapping through media-libs/ptex
python Use dev-lang/python to process source and documentation source files
tbb Enable multithreading with the Intel Threads Building Blocks through dev-cpp/tbb
tutorials Install the tutorials

opus

custom-modes Enable non-Opus modes, e.g. 44.1 kHz and 2^n frames
deep-plc Enable Deep Packet Loss Concealment (PLC)
dred Enable Deep REDundancy (DRED)
osce Enable Opus Speech Coding Enhancement (OSCE)

opusfile

fixed-point Enable fixed-point arithmetic operations
float Enable floating point arithmetic operations
http Enable http connections

osl

gui Build the osltoy binary (with Qt5)
libcxx Build against sys-libs/libcxx when using clang
nofma Do not use Fuse-Multiply-Add operations
optix Add support for NVIDIA's OptiX Raytracing Engine
partio Use media-libs/partio
qt6 Build the osltoy binary (with Qt6)

phonon

designer Install plugin for dev-qt/designer

portmidi

test-programs Install various example programs

quarter

designer Install plugin for dev-qt/designer
qch Install API documentation in QCH format
qthelp Build API documentation in QtHelp format

quirc

opencv Build tools requiring media-libs/opencv (inspect-opencv,quirc-demo-opencv)
sdl Build tools requiring media-libs/sdl-gfx (inspect, quirc-demo)
tools Build tools (qrtest)
v4l Build tools for webcams (quirc-scanner)

raptor

json Enable support for JSON parsing

raspberrypi-userland-bin

hardfp Use armv6 hardfp ABI

roc-toolkit

tools Install helper tools like roc-conv, roc-recv, roc-send

rubberband

jni Enables building of Java Native Interface library
lv2 Add support for Ladspa V2
programs Builds also executable applications
vamp Enables vamp plugins support (Audio analysing plugins)

sdl-mixer

fluidsynth Use media-sound/fluidsynth for MIDI support
midi basic support for MIDI files
mod basic support for MOD files
playtools Install playwave and playmus tools (useful for testing)
smpeg Use media-libs/smpeg for MP3 support
wav support WAVE files

sdl2-mixer

fluidsynth Use media-sound/fluidsynth for MIDI support
midi basic support for MIDI files
mod basic support for MOD files
playtools Install playwave and playmus tools (useful for testing)
tremor enable OGG Vorbis music via libtremor
wav support WAVE files

sdl2-ttf

harfbuzz Use media-libs/harfbuzz for enhanced font rendering

sdl_audiolib

fluidsynth Enable support for MIDI via media-sound/fluidsynth
mpg123 Enable support for mp3 decoding via media-sound/mpg123
openmpt OpenMPT decoder via media-libs/libopenmpt
soxr Enable SoX Resampler support via media-libs/soxr
wildmidi Enable support for MIDI via media-sound/wildmidi

sge

image enable sdl-image support

spandsp

fixed-point Enable fixed point support

speex

utils Enables speex commandline utilities (speexenc, speexdec).
vbr Enable VBR support.

suil

gtk2 Enable GTK2 based GUI support

svgalib

kernel-helper Build the helper kernel module

tremor

low-accuracy enable 32bit only multiply operations

urt

tools Install tools

vips

archive Enable support for compressed files using app-arch/libarchive
deprecated Enable deprecated components
fits Enable support for the Flexible Image Transport System data format using sci-libs/cfitsio
highway Enable SIMD optimizations using dev-cpp/highway (replaces USE=orc)
imagequant Enable support for Image Quantization using media-gfx/libimagequant
matio Enable support for matlab files using sci-libs/matio
pango Enable support for text rendering using x11-libs/pango

vulkan-loader

layers Include the vulkan layers

waffle

wayland Enable Wayland support

x264

interlaced enable interlaced encoding support, this can decrease encoding speed by up to 2%
pic disable optimized assembly code that is not PIC friendly

x265

10bit Add support for producing 10bits HEVC.
12bit Add support for producing 12bits HEVC.
numa Build with support for NUMA nodes.

xine-lib

bluray Enable playback of Blu-ray filesystems using media-libs/libbluray
dav1d Enable support for media-libs/dav1d AV1 decoder
dxr3 Enable support for DXR3 mpeg acceleration cards.
flac Build the media-libs/flac based FLAC demuxer and decoder. This flag is not needed for playing FLAC content, neither standalone nor in Ogg container (OggFLAC), but might have better support for exotic features like 24-bit samples or 96kHz sample rates.
gtk Build the gdkpixbuf-based image decoder plugin.
imagemagick Build the ImageMagick-based image decoder plugin.
mad Build the media-libs/libmad based mp3 decoder. This mp3 decoder has superior support compared to the one coming from FFmpeg that is used as a fallback. If you experience any bad behaviour with mp3 files (skipping, distorted sound) make sure you enabled this USE flag.
mmap Use mmap() function while reading file from local disks. Using mmap() will use more virtual memory space, but leaves to the Kernel the task of caching the file's data. mmap() access should be faster, but might misbehave if the device where the file resides in is removed during playback.
nfs Allow accessing NFS shares via net-fs/libnfs.
sftp Use net-libs/libssh2 to access SFTP servers.
truetype Use media-libs/freetype for font rendering and media-libs/fontconfig for font discovery. Enabling this USE flag will allow OSD (such as subtitles) to use more advanced font and to more easily select which font to use. The support for TrueType fonts in xine-lib is still experimental, and might not be as good looking as the bitmap fonts used with this USE flag disabled.
vdr Build the VDR plugin
vidix Enable support for vidix video output.
vis Adds support for SIMD optimizations for UltraSPARC processors.
vpx Enable VP8 codec support via media-libs/libvpx.
xvmc Enable support for XVideo Motion Compensation (accelerated mpeg playback).

xvid

pic disable optimized assembly code that is not PIC friendly

zita-resampler

tools Install zresample and zretune tools

zmusic

fluidsynth Enable support for MIDI via media-sound/fluidsynth
mpg123 Enable support for MPEG audio playback via media-sound/mpg123

media-plugins

alsa-plugins

arcam_av Enables Arcam AV control plugin
mix Enables upmix and vdownmix plugin
usb_stream Enables usb_stream plugin

audacious-plugins

ampache Support controlling audacious via ampache
bs2b Enable Bauer Bauer stereophonic-to-binaural headphone filter
cue Support CUE sheets using the libcue library
fluidsynth Support FluidSynth as MIDI synth backend
gme Support various gaming console music formats
http Support HTTP streams through neon
openmpt Add support for OpenMPT
pipewire Build the PipeWire output plugin
scrobbler Build with scrobbler/LastFM submission support
soxr Build with SoX Resampler support
speedpitch Enable speed/pitch effects
streamtuner Build the streamtuner plugin

calf

experimental Enable experimental features/plugins
lv2 Add support for Ladspa V2

frei0r-plugins

facedetect Enables building of facedetect plugin, which depends on media-libs/opencv
scale0tilt Enables building of scale0tilt and vectorscope plugins, which depend on media-libs/gavl

gkrellmpc

threads Use separate thread to init connection (unsafe)

grilo-plugins

chromaprint Enable Chromaprint support
daap Enable dmap support through net-libs/libdmapsharing
flickr Enable Flickr support
freebox Build support for viewing TV channels using Freebox
gnome-online-accounts Enable net-libs/gnome-online-accounts support
thetvdb Build support for thetvdb.com
tracker Build support for content discovery using the app-misc/tracker indexer
youtube Build support for YouTube content discovery using dev-libs/libgdata

gst-plugins-gtk

gles2 Enable gtkglsink OpenGL sink based on GLESv2 API
opengl Enable gtkglsink OpenGL sink based on desktop OpenGL API

gst-plugins-meta

http Enable http streaming via net-libs/libsoup
libvisual Enable visualization effects via media-libs/libvisual
vpx Enables vp8 codec support using libvpx, required to play some HTML5 videos

gst-plugins-vaapi

drm Enable DRM renderer
gles2 Enable GLESv2 and GLESv3 support

imlib2_loaders

xcf Enable XCF image loader

ir_lv2

tools Build convert4chan tool

mpg123-output-plugins

int-quality Use rounding instead of fast truncation for integer output, where possible

vdr-cdplayer

cdparanoia Enable cdparanoia (audio CD ripper) support

vdr-dvbapi

dvbcsa use media-libs/libdvbcsa free implementation of the DVB Common Scrambling Algorithm

vdr-epgsearch

conflictcheckonly install the "conflictcheckonly" vdr-plugin
epgsearchonly install the "epgsearchonly" vdr-plugin
quicksearch install the "quicksearch" vdr-plugin
tre Add support for unlimited fuzzy searching with help of dev-libs/tre library

vdr-streamdev

client Compile the VDR plugin vdr-streamdev-client that can connect a vdr to a remote streamdev-server instance
server Compile the VDR plugin vdr-streamdev-server that allows remote systems to access the vdr using streamdev-specific VTP and HTTP protocol

vdr-vdrmanager

stream Add support for streaming Video to Android client

vdr-weatherng

dxr3 enables lower osd color depth for dxr3 cards

vdr-xineliboutput

bluray Enable BluRay metadata support through media-libs/libbluray
cec Enable CEC support through dev-libs/libcec
vdr Compile the vdr output plugin to use local or remote xine as output
xine Compile the xine input plugin for displaying vdr video and OSD

media-radio

ax25-tools

X Enable some X based configuration tools.

chirp

radioreference pull in optional deps for query of radioreference

direwolf

hamlib Enables support by the Hamlib amateur radio rig control library

fldigi

hamlib Enables support by the Hamlib amateur radio rig control library to get/set frequency and mode of the ham radio in use
qt5 Build and install qtel application
rtlsdr Add support for rtlsdr hardware

tucnak

hamlib Enables support by the Hamlib amateur radio rig control library to get/set frequency and mode of the ham radio
rtlsdr Add support for rtlsdr hardware

unixcw

ncurses Enables building the curses based morse code tutor program 'cwcp'.

xastir

geotiff Install geotiff support. Allows using USGS DRG topo maps or other types of geotiff mapes/images

media-sound

abcde

aiff Enable support for Audio Interchange File Format (AIFF) output encoding
id3tag Support ID3, ID3v2 tagging of audio files
mac Enable support for Monkey's Audio files
normalize Add support for normalizing audio file volume levels
replaygain Support for Replay Gain metadata, for relative volume adjustment

abcm2ps

pango Use the pango library to render fonts with non-latin characters

alsa-utils

bat install basic audio tester (BAT) util
libsamplerate install utils that use libsamplerate (e.g. alsaloop)
ncurses install utils that use ncurses (e.g. alsamixer)

alsaplayer

id3tag Enables ID3 tagging with id3tag library

amsynth

dssi Enable support for DSSI Soft Synth Interface
lv2 Add support for Ladspa V2
nsm Build support for Non Session Manager
vst