Gentoo Linux Use Variable Descriptions

1. Global Use Flags

Flag	Description
3dfx	Enable support for Voodoo chipsets, also called as 3DFX and TDFX
3dnow	Adds support for 3dnow multimedia processor instructions
X	Adds support for X11
Xaw3d	Adds support for the 3d athena widget set
a52	Enables support for decoding ATSC A/52 streams used in DVD
aac	Enables support for MPEG-4 AAC Audio
aalib	Adds support for media-libs/aalib (ASCII-Graphics Library)
accessibility	Adds support for accessibility (eg 'at-spi' library)
acl	Adds support for Access Control Lists
acpi	Adds support for Advanced Configuration and Power Interface
adabas	Adds support for the Adabas database engine
adns	Adds support for the adns DNS client library
afs	Adds OpenAFS support (distributed file system)
aim	Enable AIM IM protocol support
alsa	Adds support for media-libs/alsa-lib (Advanced Linux Sound Architecture)
altivec	Adds support for optimizations for G4 and G5/ppc970 processors
ao	Use libao audio output library for sound playback
apache2	Add Apache2 support
apm	Adds APM (Advanced Power Management) support
arts	Adds support for aRts: the KDE sound daemon
atm	Enable Asynchronous Transfer Mode protocol support
audiofile	Adds support for libaudiofile where applicable
avahi	Add avahi/Zeroconf support
aqua	Include support for the Aqua / Carbon GUI
bash-completion	Enable bash-completion support
bcmath	Adds support for libbcmath
berkdb	Adds support for sys-libs/db (Berkeley DB for MySQL)
bidi	Enables bidirectional language support
bindist	Flag to enable or disable options for prebuilt (GRP) packages (eg. due to licensing issues)
birdstep	Adds support for the Birdstep Database Server
blas	Adds support for the virtual/blas numerical library
bluetooth	Enables Bluetooth Support
bootstrap	!!internal use only!! DO NOT SET THIS FLAG YOURSELF!, used during original system bootstrapping [make stage2]
boundschecking	Adds the bounds checking patch by Haj Ten Brugge, this will DISABLE the hardened PIE+SSP patches
branding	Enable Gentoo specific branding
bsf	Enable support for Apache Bean Scripting Framework (dev-java/bsf)
build	!!internal use only!! DO NOT SET THIS FLAG YOURSELF!, used for creating build images and the first half of bootstrapping [make stage1]
bzip2	Use the bzlib compression library
cairo	Enable support for the cairo graphics library
calendar	Adds support for calendars (not using mcal!)
canna	Adds support for the Canna kana to kanji conversion engine
caps	Use Linux capabilities library to control privilege
cdb	Adds support for the CDB database engine from the author of qmail
cdda	Adds Compact Disk Digital Audio (Standard Audio CD) support
cddb	Access cddb servers to retrieve and submit information about compact disks
cdinstall	Copies files from the CD rather than asking the user to copy them, mostly used with games
cdparanoia	Enables cdparanoia (audio CD ripper) support
cdr	Adds support for CD writer hardware
cgi	Add CGI script support
chasen	Enable chasen (Japanese Morphological Analysis System) support
cjk	Adds support for Multi-byte character languages (Chinese, Japanese, Korean)
clamav	Adds support for Clam AntiVirus software (usually with a plugin)
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
cscope	Enables cscope interface -- in vim for example
css	Enables reading of encrypted DVDs
ctype	Enables ctype functions
cups	Add support for CUPS (Common Unix Printing System)
curl	Adds support for client-side URL transfer library
curlwrappers	Adds support for using curl in streams
custom-cflags	Build with user-specified CFLAGS (unsupported)
cvs	Enable CVS (Concurrent Versions System) integration
cxx	Builds support for C++ (bindings, extra libraries, code generation, ...)
db2	Enables support for IBM DB2 database server
dbase	Adds support for dbase file format
dbi	Enable dev-db/libdbi (database-independent abstraction layer) support
dbm	Adds support for generic DBM databases
dbmaker	Adds support for dbmaker database server
dbus	Enable dbus support for anything that needs it (gpsd, gnomemeeting, etc)
dbx	Adds database abstraction layer
debug	Enable extra debug codepaths, like asserts and extra output. If you want to get meaningful backtraces see http://www.gentoo.org/proj/en/qa/backtraces.xml
dedicated	Adds support for dedicated game servers (some packages do not provide clients and servers at the same time)
dga	Adds DGA (Direct Graphic Access) support for X
directfb	Adds support for DirectFB layer (library for FB devices)
djvu	support DjVu, a PDF-like document format esp. suited for scanned documents
doc	Adds extra documentation (API, Javadoc, etc)
dri	Enable direct rendering: used for accelerated 3D and some 2D, like DMA
dts	Enables DTS Coherent Acoustics decoder support
dv	Enables support for a codec used by many camcorders
dvb	Adds support for DVB (Digital Video Broadcasting)
dvd	Adds support for DVDs
dvdr	Adds support for DVD writer hardware (e.g. in xcdroast)
eds	Enables support for Evolution-Data-Server (EDS)
emacs	Adds support for GNU Emacs
emboss	Adds support for the European Molecular Biology Open Software Suite
empress	Adds support for the Empress database server
empress-bcs	Adds local access support for the Empress database server
encode	Adds support for encoding of audio or video files
enscript	Add enscript support to colourize code stored in the repository
esd	Adds support for media-sound/esound (Enlightened Sound Daemon)
esoob	Adds support for Easysoft OOD database
evo	Adds support for mail-client/evolution
examples	Install examples, usually source code
exif	Adds 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	Adds framebuffer support for the console, via the kernel
ffmpeg	Enable ffmpeg-based audio/video codec support
fftw	Use FFTW library for computing Fourier transforms
firebird	Adds support for the Firebird relational database
firefox	Build against Firefox instead of Seamonkey/Mozilla
flac	Adds support for FLAC: Free Lossless Audio Codec
flatfile	Adds dbm support for flat files
fltk	Adds support for the Fast Light Toolkit gui interface
fontconfig	Support for configuring and customizing font access via media-libs/fontconfig
foomaticdb	Adds support for the foomatic printing driver database
fortran	Adds support for fortran (formerly f77)
freetds	Adds support for the TDS protocol to connect to MSSQL/Sybase databases
freewnn	Adds support for FreeWnn kana to kanji conversion engine
frontbase	Adds support for the frontbase sql server
ftp	Adds FTP (File Transfer Protocol) support
gcj	Enable building with gcj (The GNU Compiler for the Javatm Programming Language)
gd	Adds support for media-libs/gd (to generate graphics on the fly)
gd-external	Use the external version of gd rather than the bundled one (possibly dangerous)
gdbm	Adds support for sys-libs/gdbm (GNU database libraries)
geoip	Add geoip support for country and city lookup based on IPs
ggi	Adds support for media-libs/libggi (non-X video api/drivers)
gif	Adds GIF image support
gimp	Build a plugin for the GIMP
ginac	Adds sci-mathematics/ginac (symbolic math) support
glut	Build an OpenGL plugin using the GLUT library
gmp	Adds support for dev-libs/gmp (GNU MP library)
gnome	Adds GNOME support
gnome-keyring	Enable support for storing passwords via gnome-keyring
gnuplot	Enable support for gnuplot (data and function plotting)
gnustep	Adds integration with GNUstep environment
gnutls	Adds support for net-libs/gnutls (TLS 1.0 and SSL 3.0 support)
gphoto2	Adds digital camera support
gpm	Adds support for sys-libs/gpm (Console-based mouse driver)
gps	Adds support for Global Positioning System
graphviz	Adds support for the Graphviz library
gzip	just to commit
gsl	Use the GNU scientific library for calculations
gsm	Adds support for the gsm lossy speech compression codec
gstreamer	Adds support for media-libs/gstreamer (Streaming media)
gtk	Adds support for x11-libs/gtk+ (The GIMP Toolkit)
gtkhtml	Adds support for gnome-extra/gtkhtml
guile	Adds support for the guile Scheme interpreter
hal	Enable Hardware Abstraction Layer (HAL) support
handbook	Enable handbooks generation for KDE4.
hardened	activate default security enhancements for toolchain (gcc, glibc, binutils)
hddtemp	Enable monitoring of hdd temperature (app-admin/hddtemp)
hdf5	Adds support for the Hierarchical Data Format v5
ibm	Add support for IBM ppc64 specific systems
iconv	Enable support for the iconv character set conversion library
icq	Enable ICQ IM protocol support
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	Enables support for Imagemagick (image converter)
imap	Adds support for IMAP (Internet Mail Application Protocol)
imlib	Adds support for imlib, an image loading and rendering library
inifile	Adds dbm support for .ini files
innodb	Adds innodb support for mySQL (transaction support)
interbase	Adds support for Interbase database
iodbc	Adds support for iODBC library
ipod	Enable support for iPod device access
ipv6	Adds support for IP version 6
jabber	Enable jabber IM protocol support
jack	Adds support for the JACK Audio Connection Kit
java	Adds support for Java
java5	Use Java 1.5 to build package \|\| ( reduced deps, 1.5 features, source/target 1.5 )
java6	Use Java 1.6 to build package \|\| ( reduced deps, 1.6 features, source/target 1.6 )
javascript	Enables javascript support
jbig	enables jbig-kit support for tiff, Hylafax, ImageMagick, etc
jingle	Enables voice calls for jabber
joystick	Add support for joysticks in all packages
jpeg	Adds JPEG image support
jpeg2k	Support for JPEG 2000, a wavelet-based image compression format
kontact	Enable support for the KDE personal information manager (kde-base/kdepim*)
kde	Adds support for kde-base/kde (K Desktop Enviroment)
kdeenablefinal	EXPERIMENTAL: KDE ebuilds will use the enable-final flag, yielding compilation speedups at the cost of heavy mem usage and potentially causing problems. We strongly discourage setting this
kdehiddenvisibility	Makes KDE symbols hidden by default, requires GCC 4.1 (experimental)
kdeprefix	Makes a KDE prefixed install into /usr/kde/${SLOT} if enabled or into /usr (FHS compatible) otherwise
kerberos	Adds kerberos support
kolab	Adds support for the Kolab groupware server
krb4	Adds optional kerberos 4 compatibility support
ladspa	Enables the ability to support ladspa plugins
lame	Prefer using LAME libraries for MP3 encoding support
lapack	Adds support for the virtual/lapack numerical library
lash	Adds LASH Audio Session Handler support
latex	Adds support for LaTeX (typesetting package)
lcms	Adds lcms support (color management engine)
ldap	Adds LDAP support (Lightweight Directory Access Protocol)
libcaca	Add support for colored ASCII-art graphics
libedit	Use the libedit library (replacement for readline)
libgda	Adds GNOME Data Access support
libnotify	Enable desktop notification support
libsamplerate	Build with support for converting sample rates using libsamplerate
libwww	Adds libwww support (General purpose WEB API)
lirc	Adds support for lirc (Linux's Infra-Red Remote Control)
livecd	!!internal use only!! DO NOT SET THIS FLAG YOURSELF!, used during livecd building
lm_sensors	Adds linux lm_sensors (hardware sensors) support
lua	Enable Lua scripting support
lzo	Enables support for lzo compression
m17n-lib	Enable m17n-lib support
mad	Adds support for mad (high-quality mp3 decoder library and cli frontend)
maildir	Adds support for maildir (~/.maildir) style mail spools
mailwrapper	Adds mailwrapper support to allow multiple MTAs to be installed
matroska	Adds support for the matroska container format (extensions .mkv, .mka and .mks)
matrox	Adds Matrox MGA support to mplayer
mbox	Adds support for mbox (/var/spool/mail) style mail spools
mcve	Support for the MCVE credit card payment system
memlimit	Adds memory usage limiting in supporting programs
mhash	Adds support for the mhash library
migemo	Enables migemo support for Japanese
mikmod	Adds libmikmod support to allow playing of SoundTracker-style music files
milter	Adds sendmail mail filter (milter) support
mime	Adds MIME support
minimal	Install a very minimal build (disables, for example, plugins, fonts, most drivers, non-critical features)
mmap	Adds mmap (memory map) support
mmx	Adds support for optimizations for Pentium MMX and Athlon class processors
mng	Adds support for libmng (MNG images)
modplug	Adds libmodplug support
mono	Build Mono bindings to support dotnet type stuff
motif	Adds support for the Motif toolkit
modules	Build the kernel modules
mozilla	Adds support for the Mozilla web-browser
mp3	Add support for reading mp3 files
mp4	Support for MP4 container format
mpeg	Adds libmpeg3 support to various packages
mpi	Adds MPI (Message Passing Interface) layer to the apps that support it
mplayer	Enable mplayer support for playback or encoding
msn	Enable MSN Messenger IM protocol support
msql	Adds support for the MSQL database server
mssql	Adds support for Microsoft SQL Server database
mtp	Enable support for Media Transfer Protocol
mule	Adds multi-language support to XEmacs
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	Adds mySQL Database support
mysqli	Adds support for the improved mySQL libraries
nas	Adds support for network audio sound
ncurses	Adds ncurses support (console display library)
neXt	Enable neXt toolkit
netboot	Enables network booting
netcdf	Enable NetCDF data format support
networkmanager	Enable net-misc/networkmanager support
nis	Support for NIS/YP services
nls	Adds 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
nocxx	Disable support for C++ (DON'T USE THIS UNLESS YOU KNOW WHAT YOU'RE DOING)
nptl	Enable support for Native POSIX Threads Library, the new threading module (requires linux-2.6 or better usually)
nsplugin	Build plugin for browsers supporting the Netscape plugin architecture (that is almost any modern browser)
ocaml	Adds support/bindings for the Ocaml language
ocamlopt	Enables ocamlopt support (ocaml native code compiler) -- Produces faster programs (Warning: you have to disable/enable it at a global scale)
oci8	Adds 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	Adds ODBC Support (Open DataBase Connectivity)
offensive	Enables potentially offensive items in packages
ofx	Enable support for importing (and exporting) OFX (Open Financial eXchange) data files
ogg	Adds support for the Ogg container format (commonly used by Vorbis, Theora and flac)
old-linux	Add support for linux-2.4 and older
openal	Adds support for the Open Audio Library
openexr	Support for the OpenEXR graphics file format
opengl	Adds support for OpenGL (3D graphics)
openmp	Build support for the OpenMP (support parallel computing), requires >=sys-devel/gcc-4.2 built with USE="openmp"
oracle	Enable Oracle Database support
osc	Enables support for Open Sound Control
oscar	Enable Oscar (AIM/ICQ) IM protocol support
oss	Adds support for OSS (Open Sound System)
pam	Adds support PAM (Pluggable Authentication Modules) - DANGEROUS to arbitrarily flip
pch	Enable precompiled header support for faster compilation at the expense of disk space and memory (>=sys-devel/gcc-3.4 only)
pcmcia	Adds support for PCMCIA slots/devices found on laptop computers
pcntl	Adds support for process creation functions
pcre	Adds support for Perl Compatible Regular Expressions
pda	Adds support for portable devices
pdf	Adds general support for PDF (Portable Document Format), this replaces the pdflib and cpdflib flags
perl	Adds support/bindings for the Perl language
php	Include support for the PHP language
plasma	Build optional plasma widgets that require kde-base/libplasma
plotutils	Add support for plotutils (library for 2-D vector graphics)
png	Adds support for libpng (PNG images)
policykit	Use sys-auth/policykit to gain privileges
portaudio	Adds support for the crossplatform portaudio audio API
posix	Adds support for POSIX-compatible functions
postgres	Adds support for the postgresql database
ppds	Adds support for automatically generated ppd (printing driver) files
prelude	Adds support/bindings for the Prelude Intrusion Detection System
prefix	Defines if a Gentoo Prefix offset installation is used
profile	Adds support for software performance analysis (will likely vary from ebuild to ebuild)
pulseaudio	Adds support for PulseAudio sound server
python	Adds support/bindings for the Python language
qdbm	Adds support for the qdbm (Quick Database Manager) library
qmail-spp	Adds support for qmail SMTP plugins
qt3	Adds support for the Qt GUI/Application Toolkit version 3.x
qt4	Adds support for the Qt GUI/Application Toolkit version 4.x
quicktime	Adds support for OpenQuickTime
radius	Adds support for RADIUS authentication
raw	Add support for raw image formats
rdesktop	Adds support for the remote desktop protocol, usually used to connect to Windows servers
readline	Enables support for libreadline, a GNU line-editing library that almost everyone wants
recode	Enables support for the GNU recode library
rss	Enables support for RSS feeds
ruby	Adds support/bindings for the Ruby language
samba	Adds support for SAMBA (Windows File and Printer sharing)
sapdb	Adds support for SAP DB
sasl	Adds 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	Adds support for scanner hardware (e.g. build the sane frontend in kdegraphics)
sdl	Adds support for Simple Direct Layer (media library)
seamonkey	Adds support for the Seamonkey web-browser
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	Adds persistent session support
sharedext	Adds support for building shared extensions in PHP
sharedmem	Adds support for shared memory use
shorten	Adds support for the shorten audio compressor
simplexml	support for SimpleXML
skey	Enable S/Key (Single use password) authentication support
slang	Adds support for the slang text display library (it's like ncurses, but different)
slp	Adds Service Locator Protocol support
smartcard	Enables smartcard support
smp	Enable support for multiprocessors or multicore systems
sndfile	Adds support for libsndfile
snmp	Adds support for the Simple Network Management Protocol if available
soap	Adds support for SOAP (Simple Object Access Protocol)
sockets	Adds support for tcp/ip sockets
socks5	Adds support for the socks5 proxy
solid	Adds support for the Solid database engine
source	Zip the sources and install them
sox	Adds support for Sound eXchange (SoX)
speex	Adds support for the speex audio codec (used for speech)
spell	Adds dictionary support
spl	Adds support for the Standard PHP Library
sqlite	Adds support for sqlite - embedded sql database
sqlite3	Adds support for sqlite3 - embedded sql database
sse	fast floating point optimization for PentiumIII+ class chips
sse2	faster floating point optimization for SSE2 capable chips
ssl	Adds support for Secure Socket Layer connections
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 libraries
subversion	Enable subversion (version control system) support
suid	Enable setuid root program, with potential security risks
svg	Adds support for SVG (Scalable Vector Graphics)
svga	Adds support for SVGAlib (graphics library)
sybase	Adds support for the Sybase SQL Database Server
sybase-ct	Adds support for Sybase-CT
symlink	Force kernel ebuilds to automatically update the /usr/src/linux symlink
syslog	Enables support for syslog
sysvipc	Support for System V-compatible inter-process communication
szip	Use the szip compression library
taglib	Enable tagging support with taglib
tcl	Adds support the Tcl language
tcpd	Adds support for TCP wrappers
test	Workaround to pull in packages needed to run with FEATURES=test. Portage-2.1.2 handles this internally, so don't set it in make.conf/package.use anymore
theora	Adds support for the Theora Video Compression Codec
threads	Adds threads support for various packages. Usually pthreads
tidy	Adds support for HTML Tidy
tiff	Adds support for the TIFF image format
timidity	Build with Timidity++ (MIDI sequencer) support
tk	Adds support for Tk GUI toolkit
tokenizer	Adds support for the PHP file parser
truetype	Adds support for FreeType and/or FreeType2 fonts
uclibc	Enable uclibc specific patches and build or link uclibc
unicode	Adds support for Unicode
usb	Adds USB support to applications that have optional USB support (e.g. cups)
v4l	Enables video4linux support
v4l2	Enable video4linux2 support
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
vhosts	Adds 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
voodoo3	Adds support for 3Dfx's Voodoo3 video chipset, else defaults to Voodoo4/5 support if not in USE
vorbis	Adds support for the OggVorbis audio codec
wavpack	Add support for wavpack audio compression tools
wddx	Adds support for Web Distributed Data eXchange
wifi	Enable wireless network functions
win32codecs	use win32codecs package for dll avi decoding support (wmv and what not)
wmf	Adds support for the Windows Metafile vector image format
wxwidgets	Adds support for wxWidgets/wxGTK GUI toolkit
wxwindows	Adds support for wxWidgets/wxGTK GUI toolkit (deprecated, use wxwidgets)
x264	Enable h264 encoding using x264
xattr	Adds 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	Adds 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 the xinerama X11 extension, which allows you to stretch your display across multiple monitors
xinetd	Add support for the xinetd super-server
xml	Add support for XML files
xmlrpc	Support for xml-rpc library
xosd	Sends display using the X On Screen Display library
xpm	Adds support for XPM graphics format
xprint	Support for xprint, http://www.mozilla.org/projects/xprint/
xscreensaver	Adds support for XScreenSaver extension
xsl	Check/Support flag for XSL library (version 1)
xulrunner	Build native browser integration against xulrunner instead of firefox or seamonkey
xv	Adds in optional support for the Xvideo extension (an X API for video playback)
xvid	Adds support for xvid.org's open-source mpeg-4 codec
yahoo	Enable Yahoo Messenger IM protocol support
yaz	Adds in optional support for the Z39.50 Protocol for Information Retrieval (YAZ)
zeroconf	Support for DNS Service Discovery (DNS-SD)
zlib	Adds support for zlib (de)compression
zsh-completion	Enable zsh completion support

2. Local Use Flags

Categories

app-accessibility	app-admin	app-antivirus	app-arch	app-backup	app-benchmarks
app-cdr	app-crypt	app-dicts	app-doc	app-editors	app-emacs
app-emulation	app-forensics	app-i18n	app-laptop	app-misc	app-mobilephone
app-office	app-pda	app-portage	app-shells	app-text	app-vim
dev-cpp	dev-db	dev-dotnet	dev-embedded	dev-games	dev-haskell
dev-java	dev-lang	dev-libs	dev-lisp	dev-ml	dev-perl
dev-php	dev-php5	dev-python	dev-ruby	dev-scheme	dev-tex
dev-util	games-action	games-arcade	games-board	games-emulation	games-engines
games-fps	games-kids	games-puzzle	games-rpg	games-simulation	games-sports
games-strategy	games-util	gnome-base	gnome-extra	gnustep-apps	gnustep-base
gnustep-libs	gpe-base	kde-base	kde-misc	mail-client	mail-filter
mail-mta	media-fonts	media-gfx	media-libs	media-plugins	media-radio
media-sound	media-tv	media-video	net-analyzer	net-dialup	net-dns
net-firewall	net-fs	net-ftp	net-im	net-irc	net-libs
net-mail	net-misc	net-nds	net-news	net-nntp	net-p2p
net-print	net-proxy	net-voip	net-wireless	rox-base	rox-extra
sci-astronomy	sci-biology	sci-chemistry	sci-electronics	sci-geosciences	sci-libs
sci-mathematics	sci-misc	sci-physics	sci-visualization	sys-apps	sys-auth
sys-block	sys-boot	sys-cluster	sys-devel	sys-freebsd	sys-fs
sys-kernel	sys-libs	sys-power	sys-process	virtual	www-apache
www-apps	www-client	www-misc	www-plugins	www-servers	x11-apps
x11-base	x11-drivers	x11-libs	x11-misc	x11-plugins	x11-terms
x11-themes	x11-wm	xfce-base	xfce-extra

app-accessibility

Package	Flag	Description
brltty	api	build brltty's application program interface
	beeper	support the console tone generator
	contracted-braille	support in-line contracted braille
	fm	support for the sound card synthesizer
	learn-mode	support for interactive command learn mode
	midi	support the musical instrument digital interface
	pcm	support for sound card digital audio
	pm	user customization of Papenmeier driver
	speech	speech support
eflite	16k_voice	Use a higher-quality voice.
emacspeak	espeak	Adds support for the espeak tts engine
festival	mbrola	Adds support for mbrola voices
festival-it	mbrola	Adds support for mbrola voices
freetts	jsapi	build Java Speech API (JSAPI)
freetts	mbrola	Adds support for mbrola voices
gnome-speech	espeak	Adds support for the espeak speech driver (default)
	festival	Adds support for the festival speech driver
	freetts	Adds support for the freetts speech driver
gnopernicus	brltty	Adds support for braille displays using brltty
speech-dispatcher	espeak	Adds support for espeak speech engine
speech-dispatcher	flite	Adds support for flite speech engine

app-admin

Package	Flag	Description
bcfg2	server	Installs scripts to be used on the server-side of this app
conky	apcupsd	enable support for sys-power/apcupsd
	audacious	enable monitoring of music played by media-sound/audacious
	eve	enable support for the eve-online skill monitor
	iostats	enable support for per-task I/O statistics
	ipv6	disable support for tcp (ip4) port monitoring
	lua	enable if you want Lua scripting support
	lua-cairo	enable if you want Lua Cairo bindings for Conky (also anables lua support)
	lua-imlib	enable if you want Lua Imlib2 bindings for Conky (also enables lua and imlib support)
	math	enable support for glibc's libm math library
	moc	enable monitoring of music played by media-sound/moc
	mpd	enable monitoring of music controlled by media-sound/mpd
	nano-syntax	enable syntax highlighting for app-editors/nano
	nvidia	enable reading of nvidia card temperature sensors via media-video/nvidia-settings
	portmon	enable support for tcp (ip4) port monitoring
	smapi	enable support for smapi
	thinkpad	enable support for IBM/Lenovo notebooks
	weather-metar	enable support for metar weather service
	weather-xoap	enable support for metar and xoap weather service
diradm	automount	Support for automount data in LDAP
diradm	irixpasswd	Support for storing separate IRIX passwords
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)
	hddtemp	Enable monitoring harddrive temperatures via app-admin/hddtemp
	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
gnome-system-tools	nfs	Adds support for NFS shares
gnome-system-tools	policykit	Use sys-auth/policykit to gain privileges to change configuration files
hddtemp	network-cron	Monthly cronjob to update hddtemp.db.
lcap	lids	If you have the Linux Intrusion Detection System
prelude-manager	tcpwrapper	Add support for tcp_wrappers
puppet	augeas	Eanble augeas support
	rrdtool	Eanble rrdtool support
	shadow	Eanble shadow support
rsyslog	relp	Add support for the Reliable Event Logging Protocol using dev-libs/librelp
sshguard	ipfilter	Enable ipfilter firewall support (only for *bsd)
syslog-ng	spoof-source	Enable support for spoofed source addresses
syslog-ng	sql	Enable support for SQL destinations
sysstat	cron	Install /etc/cron.d script to periodically run sar
sysstat	isag	Install isag, the Interactive System Activity Graph tool
system-tools-backends	policykit	Use sys-auth/policykit to gain privileges to change configuration files
testdisk	ntfs	Include the ability to read NTFS filesystems
testdisk	reiserfs	include reiserfs reading ability
ulogd	mysql	Build MYSQL output plugin to save packets in a mysql database.
	pcap	Build PCAP output plugin to save packets in PCAP format. Uses the net-libs/libpcap library
	postgres	Build PGSQL output plugin to save packets in a postgres database.
	sqlite	Build SQLITE3 output plugin to save packets in an sqlite database.
webalizer	xtended	Include the 404 extension

app-antivirus

Package	Flag	Description
clamav	clamdtop	A Top like tool which shows what clamd is currently scanning amongst other things

app-arch

Package	Flag	Description
cabextract	extra-tools	Install experimental 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.
dump	ermt	encrypted rmt support
file-roller	nautilus	Enable file-roller to integrate with gnome-base/nautilus by providing entries in its context menu.
gzip	pic	disable optimized assembly code that is not PIC friendly
libarchive	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.
	lzma	Allow accessing lzma-compressed archives through the lzma library (app-arch/xz-utils). This only affects libarchive's native support: bsdtar will keep using unlzma as a filter if that's not built-in.
	static	Build bsdtar and bsdcpio as static archives, removing dependencies over the enabled compression libraries (lzma, lzmadec, libbz2, zlib).
	zlib	Allow accessing gzip-compressed archives through sys-libs/zlib. This only affects libarchive's native support: bsdtar will keep using gunzip as a filter if that's not built-in. It's also needed for supporting extraction of ZIP files.
p7zip	rar	Enable support for non-free rar decoder
rpm	magic	Add magic file support (sys-apps/file)
rpm	neon	Include support for net-misc/neon
squeeze	pathbar	Include pathbar feature
squeeze	toolbar	Include toolbar feature

app-backup

Package	Flag	Description
amanda	devpay	Support for using Amazon DevPay with S3
	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-console	Build (GUI) console program(s)
	bacula-nodir	Disable building of director in 1.38.x and later
	bacula-nosd	Disable building of storage daemon in 1.38.x and later
	logrotate	Install support files for logrotate
	logwatch	Install support files for logwatch
boxbackup	client-only	Disable server support, and just build a client
dar	dar32	Enables --enable-mode=32 option, which replace infinite by 32 bit integers
dar	dar64	Enables --enable-mode=64 option, which replace infinite by 64 bit integers
duplicity	s3	Support for backing up to the Amazon S3 system
kdar	dar32	Support libdar32.so usage
kdar	dar64	Support libdar64.so usage

app-benchmarks

Package	Flag	Description
bootchart	acct	Enable process accounting
jmeter	beanshell	Enable BeanShell scripting support

app-cdr

Package	Flag	Description
brasero	beagle	Enable app-misc/beagle support for searches
	cdrkit	Enable app-cdr/cdrkit backend
	cdrtools	Enable app-cdr/cdrtools backend
	gnome	Enable integration with the gnome-base/gnome desktop (help, session management, etc.)
	libburn	Enable dev-libs/libburn backend
	nautilus	Build gnome-base/nautilus extension
	totem	Enable support for media-video/totem playlists
cdrdao	gcdmaster	Enable building of gcdmaster application
cdrdao	pccts	Use dev-util/pccts instead of the built-in substitution
cdrkit	hfs	Provide building of HFS (Apple) CD-images
disc-cover	cdrom	Enable audio CD support. This is not needed to make www-apps/disc-cover work.
k3b	emovix	Enable burning support for eMoviX images
k3b	wav	Enable support for reading WAVE files
mybashburn	normalize	Add support for normalizing audio file volume levels
serpentine	muine	Enable support for the GNOME music player Muine
xfburn	thunar	Adds integration with Thunar file manager

app-crypt

Package	Flag	Description
ccid	nousb	Disable USB support via sys-apps/pcsc-lite
ccid	twinserial	Enable twinserial reader
ekeyd	usb	Build the libusb-based userland daemon for accessing the entropykey (alternative to the CDC USB driver).
gnupg	ecc	Use elliptic curve cryptosystem patch
	idea	Use the patented IDEA algorithm
	openct	build using dev-libs/openct compat
	pcsc-lite	build with sys-apps/pcsc-lite
gpgme	pth	Enable support for GNU Portable Threads multithreading library
heimdal	X	Building X applications
	berkdb	Berkeley DB is preferred before NDBM, but if you for some reason want to use NDBM instead, you can disable this USE flag.
	hdb-ldap	Enable support for LDAP as database backend (not suggested to use)
	ipv6	Enable/Disable ipv6 support. No magic here.
	ldap	DEPRECATED (because produces circualar dependencies): global USE which enable/disable LDAP as database backend -> see 'hd-ldap'
	otp	Enable support for one-time passwords (OTP) in some heimdal apps
	pkinit	Enable pkinit support to get the initial ticket
	ssl	Enable usage of openssl
	threads	Enable pthread support
kstart	afs	Enables afs support which means you can aquire an afs token and set PAGs. It's recommend to set this USE if you need authenticated access to an AFS cell for your daemon/app.
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.
mit-krb5	krb4	This option enables Kerberos V4 backwards compatibility using the builtin Kerberos V4 library. This is really outdated and dangerous to use because not safe.
ophcrack-tables	vistafree	Installs the free Vista ophcrack tables
	xpfast	Installs the fast XP ophcrack tables
	xpsmall	Installs the small free XP ophcrack tables
seahorse	applet	Enable seahorse applet for gnome-base/gnome-panel.
	epiphany	Enable text encryption plugin to integrate into www-client/epiphany context menu.
	gedit	Enable text encryption plugin to integrate into app-editors/gedit.
	ldap	Enable seahorse to manipulate GPG keys on a LDAP server.
	nautilus	Enable file encryption plugin to integrate into gnome-base/nautilus context menu.
	xulrunner	Selects which gecko engine against which to build the www-client/epiphany plugin.
seahorse-plugins	applet	Enable seahorse applet for gnome-base/gnome-panel
	epiphany	Enable text encryption plugin to integrate into the www-client/epiphany context menu
	gedit	Enable text encryption plugin to integrate into app-editors/gedit
	nautilus	Enable file encryption plugin to integrate into the gnome-base/nautilus context menu

app-dicts

Package	Flag	Description
aspell-be	classic	Support classic spelling by default
stardict	espeak	Enable text to speech synthesizer using espeak engine
	festival	Enable text to speech synthesizer using festival engine
	gucharmap	Enable gucharmap dictionary plugin
	pronounce	Install WyabdcRealPeopleTTS package (it is just many .wav files) to make StarDict pronounce English words
	qqwry	Enable QQWry plugin, which provides information (in Chinese language) about geographical positions, owner, etc. for IP addresses

app-doc

Package	Flag	Description
doxygen	nodot	removes graphviz dependency, along with dot graphs
heirloom-doctools	cxx	Build the mpm utility; this is disabled by default because it's rarely used and the only C++ tool in the suite.
linuxfromscratch	htmlsingle	Also install all-in-one-page HTML version
pms	all-options	Include both sides of kdebuild conditionals, shown in different colours (PDF only)
	html	Generate PMS as .html as well
	kdebuild	Include specification for the kdebuild EAPI, see http://www.gentoo.org/proj/en/desktop/kde/kdebuild-1.xml

app-editors

Package	Flag	Description
cssed	plugins	Install plugin development files
emacs	gzip-el	Compress bundled Emacs Lisp source
	hesiod	Enable support for net-dns/hesiod
	leim	Add support for Emacs input methods
	sendmail	Build Emacs with MTA support
	sound	Enable sound
	toolkit-scroll-bars	Use the selected toolkit's scrollbars in preference to Emacs' own scrollbars
emacs-cvs	gconf	Use gnome-base/gconf to read the system font name
	gzip-el	Compress bundled Emacs Lisp source
	hesiod	Enable support for net-dns/hesiod
	sound	Enable sound
	toolkit-scroll-bars	Use the selected toolkit's scrollbars in preference to Emacs' own scrollbars
fe	sendmail	Send mail after editor abend
gedit-plugins	bookmarks	Advanced Bookmarking, it remembers all the bookmarks you ever toggled, highlights them in the text and allows you to navigate through a list with the navigation pane
	bracketcompletion	Automatically adds closing brackets
	charmap	Insert special characters just by clicking on them
	colorpicker	Pick a color from a dialog and insert its hexadecimal representation
	drawspaces	Draw spaces and tabs
	joinlines	Join several lines or split long ones
	showtabbar	Add a menu entry to show/hide the tabbar
	smartspaces	Forget you're not using tabulations
	terminal	Embed a terminal in the bottom pane
gvim	aqua	Include support for the Aqua / Carbon GUI
	netbeans	Include netbeans externaleditor integration support
	nextaw	Include support for the neXtaw GUI
jasspa-microemacs	nanoemacs	Build NanoEmacs instead of MicroEmacs
joe	xterm	Enable full xterm clipboard support
jove	unix98	Use Unix 98 pty's instead of BSD pts's
leafpad	emacs	Enable Emacs key theme
nano	justify	Toggle the justify option
tea	aspell	Enable spell checking using aspell
	enchant	Enable spell checking using enchant
	hacking	Enable hacking support
	hunspell	Enable spellchecking using hunspell
vim	vim-pager	Install vimpager and vimmanpager links
vim	vim-with-x	Link console vim against X11 libraries to enable title and clipboard features in xterm
xemacs	athena	Chooses the MIT Athena widget set
	dnd	Enables support for the x11-libs/dnd drag-n-drop library
	eolconv	Support detection and translation of newline conventions
	pop	Support POP for mail retrieval
	xim	Enable X11 XiM input method
xmlcopyeditor	guidexml	Install GuideXML templates to work with Gentoo official docs
zile	valgrind	Enable usage of dev-util/valgrind in tests

app-emacs

Package	Flag	Description
auctex	preview-latex	Use bundled preview-latex
bbdb	tex	Install plain TeX support files
company-mode	ropemacs	Install backend for ropemacs (app-emacs/pymacs)
company-mode	semantic	Install backend for semantic (app-emacs/cedet)
delicious	planner	Include support for app-emacs/planner
easypg	gnus	Include support for the Gnus newsreader
emacs-common-gentoo	emacs22icons	Install Emacs 22 style icons
emhacks	jde	Enable support for Java Development Environment
remember	bbdb	Include support for app-emacs/bbdb
remember	planner	Include support for app-emacs/planner
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

Package	Flag	Description
basiliskII-jit	fbdev	Enables framebuffer support
basiliskII-jit	jit	Enables the jit compiler
bochs	debugger	Enable the bochs debugger
e-uae	capslib	Add CAPS library support
e-uae	sdl-sound	Use media-libs/sdl-sound for audio output
fuse	libdsk	Enable support for the floppy disk emulation library app-emulation/libdsk
ganeti	drbd	Enable DRBD support
	kvm	Enable KVM support
	xen	Enable Xen support
kvm	alsa	Enable alsa output for sound emulation
	esd	Enable esound output for sound emulation
	gnutls	Enable TLS support for the VNC console server
	havekernel	Don't require a kernel build tree (useful if using a binary distrbuted kernel aka binary packages)
	modules	Build the kernel modules from the kvm package
	ncurses	Enable the ncurses-based console
	pulseaudio	Enable pulseaudio output for sound emulation
	sdl	Enable the SDL-based console
	test	Build tests
	vde	Enable VDE-based networking
libvirt	iscsi	Add support for iSCSI (Internet SCSI) remote storage
	kvm	Add support for app-emulation/kvm based virtual machines
	libvirtd	Builds the libvirtd daemon as well as the client utilities instead of just the client utilities
	lvm	Add support for the Logical Volume Manager sys-apps/lvm2
	lxc	Add support for the Linux Containers
	network	Enable networking support for guests
	nfs	Allow the libvirtd daemon store VM images on NFS mounts
	numa	Use NUMA for memory segmenting via sys-process/numactl
	one	Support the ONE hypervisor protocol
	openvz	Add support for sys-kernel/openvz-sources OpenVZ-based virtual machines
	parted	Add support for the sys-apps/parted partition editor
	phyp	Support the PHYP hypervisor protocol
	qemu	Add support for app-emulation/qemu based virtual machines
	uml	Add support for User Mode Linux based virtual machines
	virtualbox	Adds support for VirtualBox based virtual machines
	xen	Add support for app-emulation/xen based virtual machines
mol	oldworld	Includes Macintosh's OldWorld support
	pci	Experimental PCI proxy support
	sheep	Support for the sheep net driver
open-vm-tools	doc	Generate API documantation
	fuse	Build vmblock-fuse in favor of FUSE based blocking mechanism for DnD
	pic	Force shared libraries to be build as PIC
	unity	Enable host unity support
pearpc	jit	Use the JITC-x86 CPU
point2play	emerald	For people who are in the Transgaming Emerald Club
q4wine	development	Enable developer related stuff
	embedded-fuseiso	Enable q4wine-mount tools
	icotools	Enable icotools support
	icoutils	Enable icoutils support
	winetools	Enable winetools support
	winetriks	Enable winetricks support
qemu	alsa	Enable alsa output for sound emulation
	esd	Enable esound output for sound emulation
	gnutls	Enable TLS support for the VNC console server
	kqemu	Enables the kernel acceleration module on a x86/x86-64 cpu
	kvm	Use the KVM (Kernel Virtual Machine) infrastructure on compatible hardware
	ncurses	Enable the ncurses-based console
	pulseaudio	Enable pulseaudio output for sound emulation
	sdl	Enable the SDL-based console
	vde	Enable VDE-based networking
qemu-softmmu	alsa	Enable alsa output for sound emulation
	esd	Enable esound output for sound emulation
	gnutls	Enable TLS support for the VNC console server
	kqemu	Enables the kernel acceleration module on a x86/x86-64 cpu
	kvm	Use the KVM (Kernel Virtual Machine) infrastructure on compatible hardware
	ncurses	Enable the ncurses-based console
	pulseaudio	Enable pulseaudio output for sound emulation
	sdl	Enable the SDL-based console
	vde	Enable VDE-based networking
uade	audacious	Enables support for media-sound/audacious
uae	scsi	Enable the uaescsi.device
	sdl-sound	Use media-sound/sdl-sound for audio output
	ui	Build the user interface (could be gtk or ncurses based, depending on sdl, dga, svga and aalib USE flags)
vice	resid	Enable support for ReSID media-libs/resid
vice	xrandr	Enable support for the X xrandr extension
virt-manager	network	Add support for creating guest networks
virtualbox-bin	additions	Install Guest System Tools ISO
	chm	Install kchmviewer binary to enable online help (in MS CHM format)
	headless	Install without any graphic frontend
	sdk	Enable building of SDK
	vboxwebsrv	Install the VirtualBox webservice
virtualbox-ose	additions	Install Guest System Tools ISO
	headless	Build without any graphic frontend
	sdk	Enable building of SDK
	vboxwebsrv	Build and install the VirtualBox webservice
vov	gprof	build with profiling support
wine	capi	Enable ISDN support via CAPI
	gecko	Add support for the Gecko engine when using iexplore
	perl	Install helpers written in perl (winedump/winemaker)
	samba	Add support for NTLM auth. see http://wiki.winehq.org/NtlmAuthSetupGuide and http://wiki.winehq.org/NtlmSigningAndSealing
	win64	Build a 64bit version of Wine (won't run Win32 binaries)
xen	acm	Enable the ACM/sHype XSM module from IBM
	flask	Enable the Flask XSM module from NSA
	pae	Enable support for PAE kernels (usually x86-32 with >4GB memory)
	xsm	Enable the Xen Security Modules (XSM)
xen-tools	acm	Enable the ACM/sHype XSM module from IBM
	api	Build the C libxenapi bindings
	flask	Enable the Flask XSM module from NSA
	hvm	Enable support for hardware based virtualization (VT-x, AMD-v
	pygrub	Install the pygrub boot loader
	screen	Enable support for running domain U console in an app-misc/screen session

app-forensics

Package	Flag	Description
afflib	ewf	Enable libewf extra formats
	fuse	Enable extra fuse thingies
	qemu	Enable qemu stuff
	s3	Enable S3
libewf	rawio	Enables raw IO handling
rdd	rawio	Enables raw IO handling
samhain	login-watch	Compile in the module to watch for login/logout events
	mounts-check	Compile in the module to check for correct mount options
	netclient	Compile a client, rather than a standalone version
	netserver	Compile a server, rather than a standalone version
	suidcheck	Compile in the module to check file system for SUID/SGID binaries
	userfiles	Compile in the module to check for files in user home directories
sleuthkit	aff	Enable extra aff formats
	dbtool	Add patch for dbtool interface from PyFlag
	ewf	Enable libewf support

app-i18n

Package	Flag	Description
ibus-table-erbi	extra-phrases	Add extra phrases into builded Engine
ibus-table-wubi	extra-phrases	Add extra phrases into builded Engine
ibus-table-zhengma	extra-phrases	Add extra phrases into builded Engine
im-ja	anthy	Support for Anthy input method
im-ja	skk	Support for SKK input method
kimera	anthy	Support for Anthy input method
libtomoe-gtk	gucharmap	Enable gucharmap dictionary plugin
scim-tomoe	gucharmap	Enable gucharmap dictionary plugin
tomoe	hyperestraier	Enable support for app-text/hyperestraier
uim	anthy	Enable support for app-i18n/anthy input method
	eb	Enable support for dev-libs/eb
	prime	Enable support for app-i18n/prime

app-laptop

Package	Flag	Description
ibam	gkrellm	Enable building of app-admin/gkrellm module
laptop-mode-tools	scsi	Adds dependency on sdparm to control non-SATA SCSI drivers
pbbuttonsd	ibam	Enable support for Intelligent Battery Monitoring
pbbuttonsd	macbook	Enable support for the Macbook and Macbook Pro
tp_smapi	hdaps	Install a compatible HDAPS module
tpctl	tpctlir	Enable support for thinkpad models 760 and 765

app-misc

Package	Flag	Description
anki	furigana	Enable support for furigana generation
	graph	Enable support for making graphs
	recording	Enable support for audio recording
	sound	Enable support for adding sound to cards
beagle	chm	Enables support for indexing of the MS CHM (Compressed HTML) file format using app-doc/chmlib.
	debug	Enables debug XML dumps of all messages passed between the daemons and the UIs. WARNING, this option will fill up your Beagle Log directory very quickly.
	doc	Builds programmer documentation for Beagle using app-doc/monodoc.
	eds	Enables Beagle to index the Addressbook and Calendar from mail-client/evolution stored in gnome-extra/evolution-data-server. The information is accessed using dev-dotnet/evolution-sharp.
	epiphany	Compiles and installs the extension for either www-client/epiphany. This extension helps Beagle index the websites you visit.
	firefox	Compiles and installs the extension for either www-client/mozilla-firefox or www-client/mozilla-firefox-bin. This extension helps Beagle index the websites you visit.
	galago	Allows Beagle to get status information from applications such as Pidgin to show in the search results.
	google	Enables google (gmail etc.) indexing support.
	gtk	Enables the GTK+ Beagle Search UI for showing search results. This is the default GUI for Beagle.
	inotify	Enable inotify filesystem monitoring support
	ole	Enables OLE (Object Linking and Editing) support via dev-dotnet/gsf-sharp, app-text/wv, and app-office/gnumeric(ssindex). These allow Beagle to index MS Powerpoint, Word, and Spreadsheet Documents.
	pdf	Enables support for indexing of the PDF (Portable Document Format) file format using `pdfinfo` and `pdftotext` from app-text/poppler
	thunderbird	Compiles and installs the extension for either mail-client/mozilla-thunderbird or mail-client/mozilla-thunderbird-bin. This extension helps Beagle index your mails.
	xscreensaver	Allow Beagle to detect when the screensaver is switched on. This allows Beagle to use more resources and index faster when the computer is not in use.
booh	transcode	Use media-video/transcode to extract video thumbnails
digitemp	ds2490	Build support for the ds2490 sensor
	ds9097	Build support for the ds9097 sensor
	ds9097u	Build support for the ds9097u sensor
fdupes	md5sum-external	Use external md5sum program instead of bundled md5sum routines
freemind	groovy	Build plugin for scripting via Groovy
	latex	Build plugin for inserting mathematical formulas in LaTeX syntax
	pdf	Build plugin for exporting mindmaps to SVG and PDF
	svg	Build plugin for exporting mindmaps to SVG and PDF
geneweb	ocamlopt	Enable ocamlopt support (dev-lang/ocaml native code compiler)
gnote	applet	Enable gnote applet for gnome-base/gnome-panel
gourmet	gnome-print	Enable printing support using gnome-print
gourmet	rtf	Enable export to RTF
gpsdrive	garmin	Adds specific support for Garmin GPS receivers (pre-2.10 only)
	gdal	Include gdal and ogr support for format conversions.
	mapnik	Include mapnik support for custom map creation.
	scripts	Include some of the additional helper scripts.
	speech	Include speech support.
gramps	mozembed	Use Mozilla-based rendering for geographical data view.
	reports	All external software that is needed for graphical reports will be installed
	webkit	Use Webkit-based rendering for geographical data view.
graphlcd-base	g15	Add support for app-misc/g15daemon driver (e.g. Logitech G15 Keybord)
lcd-stuff	mpd	Add support for display of mpd controlled music (media-libs/libmpd)
lcd4linux	mpd	Add support for display of mpd controlled music (media-libs/libmpd)
lcdproc	ftdi	Enable support for FTDI connections in some selected LCD_DEVICES (currently hd44780)
	irman	Enable support for IRMan (media-libs/libirman)
	nfs	Adds support for NFS file system
	seamless-hbars	Try to avoid gaps in horizontal bars
lirc	hardware-carrier	The transmitter device generates its clock signal in hardware
lirc	transmitter	Add transmitter support to some lirc-drivers (e.g. serial)
mc	edit	Build mcedit application
note	general	Add support for ascii flatfile backend
note	text	Add support for text backend
roadnav	festival	Enable support for app-accessibility/festival
	flite	Enable support for app-accessibility/flite (festival-lite)
	openstreetmap	Enable openstreetmap support
	scripting	Enable scripting support
screen	multiuser	Enable multiuser support (by setting correct permissions)
screen	nethack	Express error messages in nethack style
sphinx	id64	use 64-bit document and word IDs
sphinx	stemmer	Enable language stemming support
strigi	clucene	Enable dev-cpp/clucene backend support.
	hyperestraier	Enable app-text/hyperestraier backend support.
	inotify	Enable support for inotify.
	log	Enables advanced logging through dev-libs/log4cxx.
tablix	pvm	Add support for parallel virtual machine (sys-cluster/pvm)
tasque	hiveminder	Allows you to use http://www.hiveminder.com/ as your storage backend.
tasque	rememberthemilk	Allows you to use http://www.rememberthemilk.com/ as your storage backend.
tomboy	galago	Add support for the galago desktop presence framework (dev-dotnet/galago-sharp)
towitoko	moneyplex	Makes libtowitoko work for the moneyplex home banking software
tracker	applet	Build tracker monitor applet
	deskbar	Build gnome-extra/deskbar-applet plugin
	gsf	Enable gnome-extra/libgsf based data extractor
worker	avfs	Enable support for sys-fs/avfs
workrave	distribution	Enable networking. See http://www.workrave.org/features/

app-mobilephone

Package	Flag	Description
gammu	irda	Enables infrared support
gnokii	ical	Enable support for dev-libs/libical
	irda	Enable infrared support
	sms	Enable SMS support (build smsd)
obexftp	swig	Enable rebuild of dev-lang/swig bindings
smstools	stats	Enable statistic reporting
yaps	capi	Enable CAPI support

app-office

Package	Flag	Description
abiword-plugins	grammar	Enable grammar checking via dev-libs/link-grammar
	math	Enable support for x11-libs/gtkmathview
	ots	Enable Text Summarizer plugin
	thesaurus	Enable thesaurus support
	wordperfect	Enable wordperfect file support via app-text/libwpd
dia	gnome-print	Gnome-Print support (gnome-base/libgnomeprint)
gnucash	chipcard	Enable support for chipcard reading and processing.
	hbci	Enable HBCI support, for connecting to some internet banks
	quotes	Enable Online Stock Quote retrieval
	webkit	Use net-libs/webkit-gtk for rendering rather than gnome-extra/gtkhtml
gnumeric	gnome	Allow Gnumeric to use GNOME specific extensions.
	perl	Enable perl plugin loader.
	python	Enable python plugin loader.
grisbi	print	Enable printing support
imposter	iksemel	Enable external dev-libs/iksemel parsing support
karbon	pstoedit	Build support for PDF and PS import.
karbon	wpg	Build wordperfect image support.
kmymoney2	hbci	Add HBCI online banking support
kmymoney2	qtdesigner	Installs KMyMoney specific widget library for Qt-designer
krita	gmm	Enable library for sparse, dense and skyline matrices.
krita	kdcraw	Enable KDE image manipulating interface.
kspread	solver	Use solver extension for solving lingebra and others.
kword	wpd	Build wordperfect document support.
kword	wv2	Build MS-Word .doc support.
lyx	dia	Add support for diagrams (app-office/dia)
	docbook	Add support for docbook export
	dot	Add support for DOT import (media-gfx/graphviz)
	html	Add support for HTML import
	monolithic-build	This should speed up compilation significantly when you have enough RAM (>600 MB)
	rcs	Add support for revision control via app-text/rcs
	rtf	Add support for RTF import/export packages
mozilla-sunbird	moznopango	Disable pango during runtime
openoffice	binfilter	Enable support for legacy StarOffice 5.x and earlier file formats
	odk	Build the Office Development Kit
	templates	Enable installation of Sun templates
osmo	ical	Enable iCal format support
osmo	syncml	Enable syncML support
rabbit	gnome-print	Gnome-Print support (gnome-base/libgnomeprint)
	gs	Ghostscript support (virtual/ghostscript)
	tgif	tgif support (media-gfx/tgif)
texmacs	netpbm	Add support for media-libs/netpbm
tpp	figlet	Install app-misc/figlet to support the --huge command

app-pda

Package	Flag	Description
barry	boost	Enable boost support
	gui	Gui backup tool support
	opensync	Enabling opensync plugin
libopensync-plugin-irmc	irda	Enable IrDA support
libopensync-plugin-syncml	http	Enable http transports
libopensync-plugin-syncml	obex	Enable obex transports
libsyncml	http	Enable http transports
libsyncml	obex	Enable obex transports
synce	serial	Enable serial port support (installs app-pda/synce-serial)
synce-fur	void-chmod	enable a fake fuse hook for "chmod" that just returns 0

app-portage

Package	Flag	Description
conf-update	colordiff	Use colors when displaying diffs (app-misc/colordiff)
eix	bzip2	Support for parsing of environment.bz2 to guess repository name of packages installed with ancient portage versions (requires app-arch/bbzip2). This flag is safe to disable for portage users that have re-merged all packages since 2007. This flag will be phased out.
	debug	Build with CXXFLAGS/LDFLAGS for debugging support. Only makes sense in combination with FEATURES=nostrip.
	deprecated	Installs wrapper scripts for all the previous executable names that will soon be going away. Enabled by default in 0.17.0, optional in 0.18.0, removed in next major release.
	doc	Create description of the eix cache file additionally in html format
	hardened	Add CXXFLAGS/LDFLAGS enhancing security at the cost of a slight speed loss. If a hardened gcc is used, these flags should not make a difference.
	nls	Support foreign language messages (experimental; currently only de)
	optimization	Add several CXXFLAGS/LDFLAGS for optimization.
	sqlite	Compile in support for portage's sqlite backend; to actually use it you need additional configuration of portage and eix
	strong-optimization	Add more CXXFLAGS/LDFLAGS for optimization like graphite (if available). May cause trouble with some buggy compiler versions.
	tools	Create separate binary for script helper tools (currently only: versionsort); useful if they are called extremely often
gatt	libpaludis	Do some dependency resolution by using a sys-apps/paludis interface
layman	git	Support dev-util/git based overlays
pfl	network-cron	Adds a cron job which does a weekly submit of the package database
portato	userpriv	Allow emerge processes as normal user

app-shells

Package	Flag	Description
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
	plugins	Add support for loading builtins at runtime via 'enable'
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.
scsh	scsh	Use a non-FHS directory layout
scsh-install-lib	scsh	Use a non-FHS directory layout
shish	diet	Use dev-libs/dietlibc
tcsh	catalogs	Add support for NLS catalogs

app-text

Package	Flag	Description
crm114	mew	Add support for using the mewdecode mime decoder (app-emacs/mew)
	mimencode	Add support for using the mimencode mime (net-mail/metamail)
	normalizemime	Add support for using the normalizemime (mail-filter/normalizemime)
cuneiform	imagemagick	Enables support of various input formats using media-gfx/imagemagick. Otherwise only uncompressed BMP files are supported.
dictd	judy	Build Judy-based (dev-libs/judy) plugin implementing fast "exact" and especially "lev" strategies
dictd	minimal	Don't build server but dict client, dictzip and dictfmt only.
docbook-sgml-utils	jadetex	Add support for app-text/jadetex (for processing tex files produced by the TeX backend of Jade)
enchant	aspell	Adds support for app-text/aspell spell checker
	hunspell	Adds support for app-text/hunspell spell checker
	zemberek	Adds support for app-text/zemberek-server spell checker server
evince	dvi	Enable the built-in DVI viewer
	gnome	Enable the use of gnome-base/gconf to honour lockdown settings
	nautilus	Enable property page extension in gnome-base/nautilus
	t1lib	Enable the Type-1 fonts for the built-in DVI viewer (media-libs/t1lib)
hyperestraier	mecab	Enable app-text/mecab support for Estraier
lcdf-typetools	kpathsea	Enable integration with kpathsea search library (TeX related)
lodgeit	vim	Install a vim plugin allowing to paste and download from within vim
namazu	kakasi	Enable kakasi support (dev-perl/Text-Kakasi)
noweb	icon	Enable dev-lang/icon language support
pdftk	nodrm	Decrypt a document with the user_pw even if it has an owner_pw set
podofo	boost	Add support for boost
poppler-utils	abiword	Enable support for app-office/abiword output. Requires dev-libs/libxml2.
sgmltools-lite	jadetex	Add support for app-text/jadetex (for processing tex files produced by the TeX backend of Jade)
sword	lucene	Enable lucene support for faster searching (dev-cpp/clucene)
texlive	context	Add support for the ConTeXt format (dev-texlive/texlive-context)
	cyrillic	Add support for Cyrillic (dev-texlive/texlive-langcyrillic)
	detex	Add support for dev-tex/detex, a filter program that removes the LaTeX (or TeX) control sequences
	dvi2tty	Add support for dev-tex/dvi2tty to preview dvi-files on text-only devices
	dvipdfm	Add support for app-text/dvipdfm to convert DVI files to PDF
	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)
	jadetex	Add support for app-text/jadetex (for processing tex files produced by the TeX backend of Jade)
	latex3	Add support for LaTeX3 (dev-texlive/texlive-latex3)
	music	Add support for music typesetting (dev-texlive/texlive-music)
	omega	Add omega packages (dev-texlive/texlive-omega)
	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-science)
	tex4ht	Add support for dev-tex/tex4ht (for converting (La)TeX to (X)HTML, XML and OO.org)
	xetex	Add support for XeTeX macros (dev-texlive/texlive-xetex)
	xindy	Add support for app-text/xindy, a flexible indexing system
webgen	builder	Enable programmatic HTML/XML generation
	exif	Enable EXIF information in image galleries
	highlight	Enable syntax highlighting for certain plugins
	markdown	Markdown support
	thumbnail	Thumbnail creation support using rmagick
wklej	vim	Install vim plugin allowing to paste from vim by :Wklej
xpdf	nodrm	Disable the drm feature decoder

app-vim

Package	Flag	Description
gentoo-syntax	ignore-glep31	Remove GLEP 31 (UTF-8 file encodings) settings

dev-cpp

Package	Flag	Description
sptk	aspell	Enable support for app-text/aspell
sptk	excel	Enable Excel support

dev-db

Package	Flag	Description
hk_classes	mdb	Enables Microsoft Access DB support
hk_classes	xbase	Enables support for xbase databases (dBase, FoxPro, etc.)
ingres	client	Disable dbms component
	das	Enable das support
	demodb	Install demo DB
	net	Enable net support
	nodbms	Disable dbms component
libpq	pg-intdatetime	Enable --enable-integer-datetimes configure option, which changes PG to use 64-bit integers for timestamp storage
maatkit	udf	Build the MySQL UDFs shipped with maatkit, requires non-minimal MySQL
mysql	big-tables	Make tables contain up to 1.844E+19 rows
	cluster	Add support for NDB clustering
	community	Enables the community features from upstream.
	embedded	Build embedded server (libmysqld)
	extraengine	Add support for alternative storage engines
	latin1	Use LATIN1 encoding instead of UTF8
	max-idx-128	Raise the max index per table limit from 64 to 128
	minimal	Install client programs only, no server
	profiling	Add support for statement profiling (requires USE=community).
	raid	Deprecated option, removed in the 5.0 series
mysql-community	big-tables	Make tables contain up to 1.844E+19 rows
	cluster	Add support for NDB clustering
	community	Enables the community features from upstream.
	embedded	Build embedded server (libmysqld)
	extraengine	Add support for alternative storage engines
	latin1	Use LATIN1 encoding instead of UTF8
	max-idx-128	Raise the max index per table limit from 64 to 128
	minimal	Install client programs only, no server
	pbxt	Add experimental support for pbxt storage engine
	profiling	Add support for statement profiling (requires USE=community).
mysql-gui-tools	administrator	Build and install MySQL Administrator
mysql-gui-tools	query-browser	Build and install MySQL Query Browser
postgis	geos	Add the sci-libs/geos library for exact topological tests
postgis	proj	Add the sci-libs/proj library for reprojection features
postgresql	pg-intdatetime	Enable --enable-integer-datetimes configure option, which changes PG to use 64-bit integers for timestamp storage
postgresql-base	pg-intdatetime	Enable --enable-integer-datetimes configure option, which changes PG to use 64-bit integers for timestamp storage
postgresql-server	uuid	Enable server side UUID generation (via dev-libs/ossp-uuid)
sqlite	fts3	Full text search using the fts3 module
	soundex	Enable the soundex function to compute soundex encodings of strings
	threadsafe	Enable thread safe operation of sqlite

dev-dotnet

Package	Flag	Description
libgdiplus	pango	Use pango instead of cairo to render text.
nant	bootstrap	Bootstrap nant by using pre-built ndoc binaries.

dev-embedded

Package	Flag	Description
openocd	ftd2xx	Enable support for USB FTDI chips via dev-embedded/libftd2xx
	ftdi	Enable support for USB FTDI chips via dev-embedded/libftdi
	parport	Enable support for parport JTAG devices
	presto	Enable support for AXIS PRESTO devices
ponyprog	epiphany	Enable support for www-client/epiphany
sdcc	boehm-gc	Enable Hans Boehm's garbage collector (dev-libs/boehm-gc)
urjtag	ftdi	Enable support for USB FTDI chips (dev-embedded/libftdi)

dev-games

Package	Flag	Description
cegui	devil	Enable image loading via DevIL
	irrlicht	Enable the Irrlicht renderer
	xerces-c	Enable the Xerces-C++ XML parser module
crystalspace	3ds	Enables support for .3DS files in CrystalSpace
	cal3d	include support for skeleton animation
	cegui	include support for Crazy Eddie GUI
	cg	NVIDIA toolkit plugin
	ode	include support for Open Dynamics Engine
guichan	allegro	Build the Allegro frontend
ode	double-precision	more precise calculations at the expense of speed
	gyroscopic	enable gyroscopic term (may cause instability)
	nogyroscopic	disable gyroscopic term maybe improving stability
	noopcode	disable OPCODE (trimesh support)
ogre	cegui	build the CEGUI samples
	cg	NVIDIA toolkit plugin
	devil	image loading support with DevIL
	double-precision	more precise calculations at the expense of speed
openscenegraph	osgapps	Build osg applications
openscenegraph	xrandr	Enable support for the X xrandr extension
physfs	grp	Enable Build Engine GRP archive support
	hog	Enable Descent I/II HOG archive support
	mvl	Enable Descent I/II MVL archive support
	qpak	Enable Quake I/II QPAK archive support
	wad	Enable Doom WAD archive support
	zip	Enable ZIP archive support

dev-haskell

Package	Flag	Description
gtk2hs	glade	Enable gnome-base/libglade bindings compilation

dev-java

Package	Flag	Description
ant	antlr	Enable ANTLR Ant tasks
	bcel	Enable bcel (bytecode manipulation) Ant tasks
	commonslogging	Enable commons-logging Ant tasks
	commonsnet	Enable commons-net Ant tasks
	jai	Enable JAI (Java Imaging) 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
	log4j	Enable Apache log4j Ant tasks
	oro	Enable Apache Oro Ant tasks
	regexp	Enable Apache Regexp Ant tasks
	resolver	Enable Apache Resolver Ant tasks
antlr	gunit	gUnit is a "Unit Test" framework for ANTLR grammars
antlr	script	Install a script to run antlr
avalon-logkit	javamail	Enable support for javamail
avalon-logkit	jms	Enable support for JMS (Java Message Service)
commons-collections	test-framework	Install the test framework
commons-logging	avalon-framework	Add optional support for avalon-framework
	avalon-logkit	Add optional support for avalon-logkit
	log4j	Add optional support for log4j
	servletapi	Add optional support for servletapi
commons-modeler	commons-digester	Add support for the commons-digester based Mbeans Descriptor source
diablo-jdk	jce	Enable Java Cryptographic Extension Unlimited Strength Policy files
eclipse-ecj	ant	Support using ecj in Ant builds via dev-java/ant-eclipse-ecj
emma	launcher	Install /usr/bin/emma. Collides with sci-biology/emboss.
fop	hyphenation	Precompile hyphenation patterns from the dev-java/offo-hyphenation package and install them as fop-hyph.jar
	jai	Enable jai support
	jimi	Enable jimi support
gjdoc	xmldoclet	Also build support for the xml doclet that generates output in xml instead of the traditional html javadoc.
gnu-classpath	dssi	Enable the DSSI midi synthesizer provider
	gconf	Enable the GConf based util.peers backend
	gjdoc	Build GNU Classpath's javadoc implementation. Formerly dev-java/gjdoc, now part of gnu-classpath upstream.
ibm-jdk-bin	javacomm	Enable Java Communications API support
itext	rtf	Build and provide libraries for rich text format
itext	rups	Build and provide GUI for Reading/Updating PDF Syntax
jamvm	libffi	use dev-libs/libffi to call native methods
jcs	admin	Enable JCS Admin servlets
jdbc-jaybird	jni	Build/Install JDBC Type 2 native components
jdbc-mysql	c3p0	Enable c3p0 support
jdbc-mysql	log4j	Enable log4 support
jdbc-oracle-bin	dms	Enable support for the Oracle Dynamic Monitoring Service
jdbc-oracle-bin	ons	Enable support for the Oracle Notification Services (ONS) deamon
jython	servletapi	Add optional support for servlet-api
log4j	javamail	Build the SMTPAppender
	jms	Build the JMSAppender
	jmx	Build org.apace.log4j.jmx
proguard	ant	Ant task for using ProGuard in build.xml scripts
proguard	j2me	Adds support for J2ME Wireless Toolkit
qtjambi	phonon	Enable bindings to QT Phonon
	webkit	Enable bindings to QT Webkit
	xmlpatterns	Enable bindings to QT xmlpatterns
rxtx	lfd	Installs and uses LockFileServer daemon (lfd)
sun-jdk	derby	Enable Installation of Bundled Derby (Java DB)
sun-jdk	jce	Enable Java Cryptographic Extension Unlimited Strength Policy files

dev-lang

Package	Flag	Description
erlang	hipe	HIgh Performance Erlang extension
	kpoll	Enable kernel polling support
	sctp	Support for Stream Control Transmission Protocol
gdl	hdf	Adds support for the Hierarchical Data Format
gdl	proj	Adds proj library support (geographic projections)
gforth	force-reg	Enable a possibly unstable GCC flag for possibly large performance gains
ghc	binary	Install the binary version directly, rather than using it to build the source version.
ghc	ghcbootstrap	Internal: Bootstrap GHC from an existing GHC installation.
icc	eclipse	Install the dev-util/eclipse-sdk plugins
	idb	Install the Intel Debugger
	ipp	Install the Intel Integrated Primitive
	mkl	Install the Intel Math Kernel Library
icon	iplsrc	install the icon programming library source
idb	eclipse	Install the dev-util/eclipse-sdk plugins
	icc	Use dev-lang/icc to install idb (default)
	ifc	Use dev-lang/ifc to install idb
ifc	idb	Install the Intel Debugger
ifc	mkl	Install the Intel Math Kernel Library
lisaac	vim	install a syntax file for vim
logtalk	fop	Support for generating pdf documentation using fop
	gnupl	Support GNU Prolog back-end compiler
	qupl	Support Qu-Prolog back-end compiler
	swipl	Support SWI-Prolog back-end compiler
	xsbpl	Support XSB back-end compiler
	xslt	Support for generating html documentation using xslt
	yappl	Support YAP back-end compiler
lua	deprecated	make deprecated data structures/routines available
luarocks	curl	Uses net-misc/curl for fetching lua packages instead of net-misc/wget.
luarocks	openssl	Uses dev-libs/openssl for verifying lua packages instead of md5sum.
mlton	binary	install a binary version (need to do this once to bootstrap, until smlnj is supported)
mono	moonlight	Generate Moonlight 2.1 assemblies
mono	xen	Make mono generate code that is considerably faster on xen VMs but slightly slower on for normal systems.
perl	ithreads	Enable Perl threads, has some compatibility problems
perl	perlsuid	Enable Perl SUID install. Has some risks associated.
php	cli	Enable CLI SAPI
	concurrentmodphp	Make it possible to load both mod_php4 and mod_php5 into the same Apache2 instance (experimental)
	discard-path	Switch on common security setting for CGI SAPI
	fastbuild	Build PHP quicker (experimental)
	fdftk	Add supports for Adobe's FDF toolkit.
	filter	Add filter extension support
	force-cgi-redirect	Switch on common security setting for CGI SAPI
	hash	Enable the hash extension
	java-external	Use the external java extension rather than the bundled one
	json	Enable JSON support
	ldap-sasl	Add SASL support for the PHP LDAP extension
	pdo	Enable the bundled PDO extensions
	pic	Force shared modules to build as PIC on x86 (speed tradeoff with memory usage)
	reflection	Enable the reflection extension (Reflection API)
	suhosin	Add Suhosin support (patch and extension from http://www.suhosin.org/)
	xmlreader	Enable XMLReader support
	xmlwriter	Enable XMLWriter support
	zip	Enable ZIP file support
python	threads	Enable threading support (DON'T DISABLE THIS UNLESS YOU KNOW WHAT YOU'RE DOING)
	ucs2	Enable byte size 2 unicode (DON'T USE THIS UNLESS YOU KNOW WHAT YOU'RE DOING)
	wininst	Install required Windows executables to create an executable installer for MS Windows.
ruby	rubytests	Install ruby tests that can only be run after ruby is installed
scala	binary	Install from (Gentoo-compiled) binary instead of building from sources. Set this when you run out of memory during build.
spidermonkey	threadsafe	Build a threadsafe version of spidermonkey
swig	R	Enable R support
	chicken	Enable chicken Scheme support
	clisp	Enable CLisp support
	mzscheme	Enable PLT mzscheme support
	octave	Enable Octave support
	pike	Enable Pike scripting support
vala	coverage	Enable coverage analysis
vala	vapigen	Enable vala's library binding generator

dev-libs

Package	Flag	Description
DirectFB	fusion	Add Multi Application support (fusion kernel device)
DirectFB	sysfs	Add support for the sysfs filesystem (requires Linux-2.6+)
STLport	boost	Enable the usage of dev-libs/boost
ace	ciao	Include Component Intergraced Ace ORB into the build of ace
ace	tao	Include the ACE ORB (CORBA stuff) (called tao) into the build of ace
apr	older-kernels-compatibility	Enable binary compatibility with older kernels
apr	urandom	Use /dev/urandom instead of /dev/random
boolstuff	static	Enable static linking
boost	bcp	Install the bcp tool http://www.boost.org/tools/bcp/bcp.html
	bjam	Install the BoostJam tool http://www.boost.org/tools/build/jam_src/index.html
	eselect	Run "eselect boost update" even if version is already selected
	pyste	Add support for the pyste frontend
	threadsonly	Only build multithreaded libs
	tools	Build and install the boost tools (bcp, quickbook, inspect, wave)
crypto++	sse3	Enable optimizations via sse3 assembly code
cyberjack	noudev	Disable installation of udev rules
cyberjack	pcsc-lite	Enable installation of sys-apps/pcsc-lite driver
cyrus-sasl	authdaemond	Enable Courier-IMAP authdaemond's unix socket support (net-mail/courier-imap, mail-mta/courier)
	ntlm_unsupported_patch	Add NTLM net-fs/samba NOT supported patch
	sample	Build sample client and server
	srp	Enable SRP
	urandom	Use /dev/urandom instead of /dev/random
eggdbus	largefile	Support for large files
elfutils	lzma	Support automatic decompression of LZMA-compressed files and kernel images.
fcgi	html	Install HTML documentation
ferrisloki	stlport	Include support for dev-libs/STLport
geoip	perl-geoipupdate	Install pure perl version of geoipupdate, with Proxy Server support via via the "http_proxy" environment variable and easy to customize.
klibc	n32	Force klibc to 32bit if on mips64 if not n32 userland
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.
libgcrypt	idea	Use the patented IDEA algorithm
libjit	interpreter	Enable the libjit interpreter
	long-double	Enable the use of long double for jit_nfloat
	new-reg-alloc	Enable new register allocator
libmemcached	hsieh	Use Hsieh hash algorithm.
libmix	no-net2	Disable support for virtual/libpcap and net-libs/libnet
libprelude	easy-bindings	Enable support for high level bindings (available for C++, Perl, Python)
libprelude	swig	Enable rebuild of swig bindings
libpreludedb	swig	Enable rebuild of swig bindings
libsqlora8	orathreads	Use Oracle threads
libtomcrypt	libtommath	Use the portable math library (dev-libs/libtommath)
libtomcrypt	tomsfastmath	Use the optimized math library (dev-libs/tomsfastmath)
log4cxx	smtp	Offer SMTP support via net-libs/libesmtp
nss	utils	Install utilities included with the library
opencryptoki	tpmtok	Offer support for TPM token
openct	pcsc-lite	Enable support for sys-apps/pcsc-lite
openobex	irda	Enable IrDA support
opensc	openct	Build using dev-libs/openct compatibility
opensc	pcsc-lite	Build with sys-apps/pcsc-lite
pkcs11-helper	nss	Enable NSS crypto engine
poppler	abiword	Enable support for app-office/abiword output. Requires dev-libs/libxml2.
poppler	poppler-data	Pull in the free (as in beer) poppler-data package which is required at runtime for complete rendering of CJK PDFs.
ppl	prolog	Build SWI Prolog interface
ppl	watchdog	Build the PPL Watchdog library - a C++ library for multiple, concurrent watchdog timers
qsa	ide	Enable the qsa ide
soprano	clucene	Enable dev-cpp/clucene backend support (java app).
	raptor	Enables support for media-libs/raptor RDF parser/serializer.
	redland	Enables support for the dev-libs/redland backend (really slow one).
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)
	libwww	Use the net-libs/libwww library for fetching URLs, instead of the builtin method
	threads	Enable threading support through pthread (or other libraries on AIX, IRIX, HPUX, Solars). Highly recommended
	xqilla	Apply patches from the XQilla project and install additional header files
xml-security-c	xalan	Enable support for XSLT and XPath parsing by dev-libs/xalan-c
xmlrpc-c	abyss	Build the Abyss mini web-server.
	threads	Controls whether to build the Abyss web-server with pthreads or fork 'threading'.
	tools	Build the xmlrpc* tools.
xqilla	faxpp	Use dev-libs/faxpp instead of Xerces-C for certain tasks
xqilla	htmltidy	Use app-text/htmltidy when parsing HTML
yaz	ziffy	Install ziffy, a promiscuous Z39.50 APDU sniffer

dev-lisp

Package	Flag	Description
abcl	clisp	Build Armed Bear Common Lisp using GNU CLISP
	cmucl	Build Armed Bear Common Lisp using CMU Common Lisp
	jad	Enable support for disassembling compiled code using JAD
cl-tbnl	standalone	Use TBNL without a front-end (ie. no Apache dependency)
clisp	hyperspec	Use local hyperspec instead of online version
	new-clx	Build CLISP with support for the NEW-CLX module which is a C binding to the Xorg libraries
	pari	Build CLISP with support for the PARI Computer Algebra System
	svm	Build CLISP with support for the Support Vector Machine module
cmucl	nosource	Don't include source code for CMUCL in installation
ecls	c++	Build ECL with a C++ compiler
	threads	Support for native threads
	unicode	Support for unicode
gcl	ansi	Build a GCL with ANSI support (else build a traditional CLtL1 image)
	custreloc	Build a GCL which uses custom GCL code for linking
	dlopen	Build a GCL which uses dlopen for linking
	gprof	Build a GCL with profiling support
sbcl	cobalt	mips only: use mipsel binary instead of mips big endian binary to bootstrap
sbcl	ldb	Include support for the SBCL low level debugger

dev-ml

Package	Flag	Description
camlimages	gs	Ghostscript support (virtual/ghostscript)
lablgtk	glade	Enable libglade bindings compilation.
	gnomecanvas	Enable libgnomecanvas bindings compilation.
	sourceview	Enable GtkSourceView support
ocamlnet	httpd	Enables net-httpd web server component
ocamlnet	zip	Enables netzip support to read/write gzip data using object channels

dev-perl

Package	Flag	Description
App-Nopaste	clipboard	copying of URLs with -x/--copy
	github	Github authentication
	pastebin	pastebin.com support
Eidetic	auth	Enables dev-perl/Apache-AuthTicket based cookie authentication
GD	animgif	Enable animated gif support
HTML-Mason	modperl	Enable www-apache/mod_perl support
PDL	badval	Enable badval support

dev-php

Package	Flag	Description
PEAR-PHP_Shell	auto-completion	Enable tab-completion

dev-php5

Package	Flag	Description
ZendFramework	cli	Enables the CLI
	doc	Installs the documentation
	examples	Installs the examples
	minimal	Installs the minimal version without Dojo toolkit, tests and demos
eaccelerator	contentcache	Enable content caching
	disassembler	Enable the eA disassembler
	inode	Use inode-based caching
php-gtk	extra	Enable GtkExtra support
	glade	Enable libglade support
	libsexy	Enable libsexy support
	mozembed	Enable GtkMozembed support
	scintilla	Enable Scintilla support

dev-python

Package	Flag	Description
PyQt4	X	Build the QtGui and QtDesigner modules
	assistant	Build the QtHelp and QtAssistant modules
	kde	Select media-sound/phonon as phonon variant needed for kde
	opengl	Build the QtOpenGL module
	phonon	Build the phonon module
	qt3support	Enable the Qt3Support libraries for Qt4
	sql	Build the QtSql module
	svg	Build the QtSvg module
	webkit	Build the QtWebKit module
	xmlpatterns	Build the QtXmlPatterns module
cgkit	3ds	Enable support for importing 3D Studio models
dap	server	Enable OpenDAP server support
docutils	glep	Install support for GLEPs
jinja2	i18n	Enables support for i18n with dev-python/Babel
kaa-base	tls	SSL/TLS support via dev-python/tlslite
ldaptor	web	enable the web front end for ldaptor (uses dev-python/nevow)
markdown	pygments	Enable fancy pygments support
matplotlib	excel	Pull dev-python/xlwt for the exceltools toolkit
matplotlib	traits	Pull dev-python/traits for the experimental enthought traits support
paste	flup	enable support for flup (and therefore for various wgsi servers and middleware)
paste	openid	enable OpenID support
psycopg	mxdatetime	Enable support for MX DateTime and use it instead of Python's built-in datetime module
pygobject	libffi	Enable support to connect to signals on python objects from C.
pylons	cheetah	Add optional cheetah support
	genshi	Add optional genshi support
	jinja2	Add optional jinja2 support
	kid	Add optional kid support
	mako	Add optional mako support
	myghty	Add optional myghty support
pyyaml	libyaml	enable libyaml support
pyzor	pyzord	enable support for pyzord
rdflib	redland	enable support for Redland triplestore
rdflib	zodb	enable support for Zope Object Database triplestore
soya	ode	include support for Open Dynamics Engine
spyder	matplotlib	Add support for dev-python/matplotlib
	mayavi	Add support for sci-visualization/mayavi
	numpy	Add support for dev-python/numpy
	pylint	Add support for dev-python/pylint
	scipy	Add support for sci-libs/scipy
sympy	imaging	Add support for dev-python/imaging
	ipython	Add support for dev-python/ipython
	mathml	Add support for mathml
	texmacs	Add support for app-office/texmacs
twisted	serial	include serial port support
visual	numarray	enable support for numarray
visual	numeric	enable support for numeric
wxpython	doc	Install HTML wxWidgets docs and wxpython API reference.
wxpython	examples	Install interactive demo module browser and sample applets.
zsi	twisted	add support for dev-python/twisted

dev-ruby

Package	Flag	Description
camping	mongrel	Also install www-servers/mongrel
nitro	lighttpd	Also install www-servers/lighttpd
nitro	xslt	Enable dev-libs/libxslt support
og	kirbybase	Enable dev-ruby/kirbybase support
ruby-sdl	image	Enable media-libs/sdl-image support
	mixer	Enable media-libs/sdl-mixer support
	sge	Enable sdl-sge support
rubygems	server	Install support for the rubygems server
sqlite3-ruby	swig	Use dev-lang/swig to generate bindings

dev-scheme

Package	Flag	Description
bigloo	bee	Bigloo integrated development environment
gauche-gl	cg	Enable NVidia Cg binding
gauche-gtk	glgd	Enable GL graph draw
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
	elisp	Enable Emacs Lisp support
	networking	Include networking interfaces
	regex	Include regular expression interfaces
plt-scheme	backtrace	Support GC backtrace dumps
	cgc	Compile and install additional executables which use the conservative garbage collector
	llvm	Add support for compiling to the low-level virtual machine (llvm)

dev-tex

Package	Flag	Description
dot2texi	pgf	Enable support for dev-tex/pgf (The TeX Portable Graphic Format)
dot2texi	pstricks	Enable pstricks support
latex-beamer	lyx	Install with app-office/lyx layouts

dev-util

Package	Flag	Description
anjuta	devhelp	Enable devhelp integration
	glade	Build glade plugin for anjuta
	inherit-graph	Build inheritance graphing plugin for anjuta
	sourceview	Build sourceview editing plugin for anjuta
	symbol-db	Enable symbol database plugin for anjuta
	valgrind	Build valgrind plugin for anjuta
astyle	libs	builds and installs both shared and static library interfaces
buildbot	irc	Add support for status delivery through an ircbot.
	mail	Add support for watching a maildir for commits.
	manhole	Add support for manhole (debug over ssh)
bzr	sftp	Enable sftp support
catalyst	ccache	Enables ccache support
codeblocks	contrib	Build additional contrib components
ctags	ada	Enable Ada support
cvs	server	Enable server support
dialog	minimal	Disable library, install command-line program only
gambas	corba	Enable CORBA 2 ORB (net-misc/omniORB)
gambas	smtp	Enable smtp support.
geany	vte	Enable Terminal support (x11-libs/vte)
git	blksha1	Use the new optimized SHA1 implementation.
	cgi	Install gitweb too
	gtk	Include the gitview contrib tool.
	mozsha1	Makes git use an optimized SHA1 routine from Mozilla that should be fast on non-x86 machines.
	ppcsha1	Make use of a bundled routine that is optimized for the PPC arch.
	subversion	Include git-svn for dev-util/subversion support.
	webdav	Adds support for push'ing to HTTP repositories via DAV.
global	vim	Integrate the GNU GLOBAL source code tag system with Vim
kdevelop	cmake	Support for the CMake Build System.
kdevelop	qmake	Support for the QMake Build System.
kdevplatform	git	Add suport for git VCS
kdevplatform	mercurial	Add suport for mercurial VCS
mercurial	bugzilla	Support bugzilla integration.
	gpg	Support signing with GnuPG.
	tk	Install dev-lang/tk for hgk script.
metro	ccache	Enable support for ccache
	git	Enable support for git snapshots
	threads	Enable support for pbzip2 tarball packing/unpacking
mono-tools	webkit	Use net-libs/webkit-gtk for rendering.
nemiver	memoryview	Enable the optional hexadecimal memory inspection with app-editors/ghex.
netbeans	cxx	Adds Netbeans C/C++ Pack
nsis	config-log	Enable the logging facility (useful in debugging installers)
nvidia-cuda-sdk	emulation	Build binaries for device emulation mode. These binaries will not require a CUDA-capable GPU to run.
nvidia-cuda-toolkit	debugger	Installs the CUDA debugger.
nvidia-cuda-toolkit	profiler	Installs the NVIDIA CUDA visual profiler.
pbuilder	uml	Enable pbuilder user mode linux support
perf	demangle	Enable C++ symbol name demangling, using libbfd from sys-devel/binutils. When this flag is enabled, the package will have to be rebuilt after every version bump of binutils.
perf	doc	Build documentation and man pages. With thise 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.
qct	bazaar	Support for dev-util/bzr
	mercurial	Support for dev-util/mercurial
	monotone	Support for dev-util/monotone
qt-creator	bineditor	enable bineditor plugin
	bookmarks	enable bookmarks plugin
	cmake	enable cmake project manager plugin
	debugger	enable debugger plugin
	designer	enable designer plugin
	fakevim	enable vim-like key bindings plugin
	git	enable git plugin
	perforce	enable perforce software configuration manager plugin
	qtscript	enable qt script editor plugin
	subversion	enable subersion plugin
radare	gui	Enable the graphical user interface of radare (broken)
radare	vala	Enable support for the vala programming language
schroot	dchroot	Enables the building of a wrapper named "dchroot", replacing dev-util/dchroot.
strace	aio	Enable libaio support
subversion	ctypes-python	Build and install ctypes python bindings
	dso	Enable runtime module search
	extras	Install extras scripts (examples, tools, hooks)
	webdav-neon	Enable WebDAV support using net-misc/neon
	webdav-serf	Enable WebDAV support using net-libs/serf
svk	log4p	Enable perl logger support
	pager	Enable perl pager selection support
	patch	Enable patch creation, import support
universalindentgui	html	Add support for HTML files

games-action

Package	Flag	Description
abuse	demo	Use the demo data instead of the full game
	levels	Install user-created levels (fRaBs)
	sounds	Install optional sound data
chromium	mixer	Enables media-libs/sdl-mixer sound backend instead of media-libs/openal one.
d1x-rebirth	awe32	Enable AWE32 support
	demo	Use the demo data instead of the full game
	mixer	Enable mixer support
	mpu401	Enable MPU401 music support
d2x-rebirth	awe32	Enable AWE32 support
d2x-rebirth	mpu401	Enable MPU401 music support
xshipwars	yiff	Add support for the YIFF sound server

games-arcade

Package	Flag	Description
bomns	editor	enables building the level editor
lbreakout2	themes	Install additional themes
moleinvasion	music	Download and install the music files
smc	music	Download and install the music files
stepmania	force-oss	force using OSS
triplexinvaders	psyco	psyco python accelerator
tuxanci	sound	Enable sound
ultrastar-ng	songs	Install a few demo songs
ultrastar-ng	video	Enable smpeg video support

games-board

Package	Flag	Description
chessdb	tb4	Install 4 pieces table bases
crafty	no-opts	Don't try to enable crazy CFLAG options
freedoko	altenburgcards	Use the Altenburg card set
	kdecards	Use the KDE card set
	net	Enable network game support
	pysolcards	Use the PySol card set
	xskatcards	Use the XSkat card set
grhino	gtp	Install the GTP (Go/Game Text Protocol) frontend
pysol	extra-cardsets	Install extra cardsets
spider	xaw	Enable athena widgets
xboard	zippy	Enable experimental zippy client

games-emulation

Package	Flag	Description
generator	sdlaudio	Enable SDL Audio
snes9x	netplay	Enable playing ROMs over the network (not recommended)
xmame	net	Add network support
xmess	net	Add network support

games-engines

Package	Flag	Description
frobtads	tads2compiler	Build TADS2 compiler
frobtads	tads3compiler	Build TADS3 compiler
scummvm	fluidsynth	compile with support for fluidsynth

games-fps

Package	Flag	Description
darkplaces	cdsound	Enables using CD audio in the engine
	demo	Uses the demo data from quake1 (quake1-demodata)
	dpmod	Sets up the darkplaces mod from icculus
	lights	Install and setup the updated light maps
	textures	Install and setup the updated textures
doom-data	doomsday	Add wrapper to run it within doomsday
doom3	roe	Adds support for the Resurrection of Evil expansion
duke3d	demo	Install the demo files
duke3d	pic	disable optimized assembly code that is not PIC friendly
ezquake-bin	security	install the security module needed for some servers
freedoom	doomsday	Add wrapper to run it within doomsday
nexuiz	maps	Install the community map pack
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)
quake3	teamarena	Adds support for Team Arena expansion pack
quake3-bin	teamarena	Adds support for Team Arena expansion pack
qudos	demo	Install the demo files (quake2-demodata) and configure for use
	mods	Build support for the quake2 mission packs
	qmax	Build the pretty version (quake max)
	textures	Install the enhanced textures (quake2-textures)
rott	demo	Install the shareware version
unreal-tournament-goty	S3TC	Add the extra fancy textures to UT ... only works on certain cards (nvidia/ati/s3)
warsow	angelscript	Enable AngelScript support
warsow	irc	Enable IRC support
worldofpadman	maps	Install extra maps (PadPack)

games-kids

Package	Flag	Description
gcompris	gnet	will let GCompris fetch content from a web server

games-puzzle

Package	Flag	Description
jag	editor	Install level editor
jag	extras	Install additional graphics
xlogical	alt_gfx	Use alternate graphics which are closer to the original Amiga version

games-rpg

Package	Flag	Description
drascula	audio	Install optional audio files
eternal-lands-data	music	Install optional music files (extra 30 meg)
eternal-lands-data	sound	Install optional sound files (extra 40 meg)
galaxymage	psyco	psyco python accelerator
mangos	ahbot	include the AHBot-patch
	cli	compiles with support command line system
	ra	compiles with support remote console system
	sd2	includes ScriptDev2 to distribution
	tools	include additional tools, such as the ad map extractor
nwn	hou	Install the Hordes of the Underdark expansion pack
nwn	sou	Installs the Shadows of Undrentide expension pack
nwn-cep	hou	Adds support for the Hordes of the Underdark expansion pack
nwn-cep	sou	Adds support for the Shadows of Undrentide expension pack
nwn-data	hou	Install the Hordes of the Underdark expansion pack
	nowin	For those people who cant grab the 1.2 gigs of data files from a windows partition
	sou	Installs the Shadows of Undrentide expension pack

games-simulation

Package	Flag	Description
singularity	music	Install music files

games-sports

Package	Flag	Description
xmoto	editor	Depend on inkscape, scripts to convert svg to level (svg2lvl)

games-strategy

Package	Flag	Description
dark-oberon	fmod	Add sound support (fmod)
defcon-demo	system-libs	Use system libraries instead of the ones included in the upstream distribution.
freeciv	auth	Add authentication capability
freelords	editor	Installs optional map editor
glest	editor	Also install a level editor
heroes3	maps	Installs optional map data
	music	Installs optional music data
	sounds	Installs optional sound data
ufo-ai	editor	Build map editor
uqm	music	download and install music files (large)
	remix	download and install music remix files (large)
	voice	download and install voice files (large)
wesnoth	server	Enable compilation of server
wesnoth	tinygui	enable GUI reductions for resolutions down to 320x240 (PDAs)
x2	bonusscripts	Add bonus scripts
	dynamic	Use dynamic binaries instead of static
	langpacks	Install additional language packs
	modkit	Install the modkit

games-util

Package	Flag	Description
gslist	web	Enable the web interface

gnome-base

Package	Flag	Description
gdm	consolekit	Allow proper handling of removable media according to who is actually present on the machine.
	dmx	Enables Distributed Multihead X (DMX) support
	remote	Enables support for secure remote connections
	xklavier	Use x11-libs/libxklavier for keyboard management
gnome-control-center	sound	Enable sound event support with media-libs/libcanberra
gnome-mount	nautilus	Enables the Nautilus plugin
gnome-session	policykit	Enable sys-auth/policykit authentication support
gnome-session	splash	Enable gnome splash screen
gnome-volume-manager	automount	Enable support for automounting devices that are handled by gnome-base/nautilus since 2.22. This should be off on most Gnome systems.
gnome-volume-manager	consolekit	Use sys-auth/consolekit to determine policy on removable media.
gvfs	archive	Enables support for accessing files in archives transparently via app-arch/libarchive
	fuse	Enables fuse mount points in $HOME/.gvfs for legacy application access
	gdu	Enable sys-apps/gnome-disk-utility integration
	udev	Enable udev base replacement code for cdda feature
nautilus	beagle	Enables support for searching using the Beagle (app-misc/beagle) desktop search tool
	tracker	Enables support for searching using the Tracker (app-misc/tracker) search tool
	xmp	Adds support for XMP metadata

gnome-extra

Package	Flag	Description
avant-window-navigator	vala	Enables support for applets written in dev-lang/vala.
avant-window-navigator	xfce	Enables support for the XFCE 4 desktop environment
avant-window-navigator-extras	webkit	Enables support for net-libs/webkit-gtk.
file-browser-applet	gtkhotkey	Enable hotkey support via x11-libs/gtkhotkey
gget	epiphany	Install epiphany extensions
gnome-do-plugins	banshee	Enables the Banshee (media-sound/banshee) plugin
gnome-games	artworkextra	Installs extra artwork for various games
gnome-lirc-properties	policykit	Use sys-auth/policykit to gain privileges to change configuration files
gnome-media	gnomecd	Builds the GNOME CD Player
gnome-media	sound	Adds support for sound notification themes using media-libs/libcanberra
gnome-power-manager	policykit	Enable sys-auth/policykit authentication support
gtkhtml	glade	Provide integration with dev-util/glade.
libgda	mdb	Enables Microsoft Access DB support
libgda	xbase	Enables support for xbase databases (dBase, FoxPro, etc.)
libgsf	gtk	Enable use of gdk in thumbnailer
music-applet	mpd	Enable MPD support
nautilus-sendto	eds	Enables support for evolution-sendto using gnome-extra/evolution-data-server
	empathy	Enables support for net-im/empathy
	gajim	Enables support for net-im/gajim
	mail	Enables support for mailto using gnome-extra/evolution-data-server
	pidgin	Enables support for net-im/pidgin
	sylpheed	Enables support for mail-client/sylpheed
	thunderbird	Enables support for mail-client/mozilla-thunderbird
	upnp	Enables support for sending files over upnp using net-libs/gupnp-av
sensors-applet	nvidia	Enables support for sensors on NVidia chips
yelp	beagle	Enables support for the Beagle (app-misc/beagle) desktop search tool
yelp	lzma	Enables support for LZMA compressed info and man pages

gnustep-apps

Package	Flag	Description
cdplayer	preferences	Use gnustep-apps/preferences for preferences setting
cdplayer	systempreferences	Use gnustep-apps/systempreferences for preferences setting
gnumail	emoticon	Enable extra Emoticon Bundle to see smiley's in e-mail messages

gnustep-base

Package	Flag	Description
gnustep-back-art	xim	Enable X11 XiM input method
gnustep-back-cairo	glitz	Build with media-libs/glitz support
gnustep-back-cairo	xim	Enable X11 XiM input method
gnustep-back-xlib	xim	Enable X11 XiM input method
gnustep-base	libffi	Use dev-libs/libffi instead of dev-libs/ffcall
gnustep-make	native-exceptions	Enables use of the native Objective-C exception support (@try/@catch/@finally) built-in objective-c exceptions with compilers that support it

gnustep-libs

Package	Flag	Description
steptalk	gdl2	Compile module for gnustep-libs/gdl2

gpe-base

Package	Flag	Description
gpe	games	Builds and installs GPE games.

kde-base

Package	Flag	Description
ark	archive	Enable support for a variety of archive formats through libarchive
	lzma	Enable lzma support
	zip	Enable zip support through LibZip
dolphin	semantic-desktop	Semantic desktop allows for storage of digital information and its metadata to allow the user to express his personal mental models, making all information become intuitively accessible.
dolphin	thumbnail	Enables video thumbnails generation for kde-base/dolphin file manager.
gwenview	kipi	Support for the KDE Image Plugin Interface.
kaddressbook	gnokii	Address synchronization with mobile phones via app-mobilephone/gnokii
kalzium	editor	Enable the embedded molecule editor/viewer
kalzium	solver	Enable the equation solver
kcontrol	logitech-mouse	Build the Control Center module to configure logitech mice
kdeadmin-meta	lilo	Install lilo-config, a frontend for the lilo boot loader
kdeartwork-kscreensaver	eigen	Enable various aritmethic screensavers which use Eigen2 for computations.
kdebase-kioslaves	lzma	Enable lzma support
kdebindings-csharp	akonadi	Compile bindings for kde-base/akonadi.
	phonon	Compile bindings for media-sound/phonon.
	plasma	Compile bindings for kde's plasma.
	qscintilla	Compile bindings for x11-libs/qscintilla.
	webkit	Compile bindings for x11-libs/webkit.
kdelibs	legacyssl	Support for some deprecated ciphers. Don't use this flag unless you really need it
	lzma	Enable lzma support
	utempter	Records user logins. Useful on multi-user systems
kdeplasma-addons	desktopglobe	Enable Desktop Globe wallpaper using kde-base/marble.
kdeutils-meta	floppy	Install kfloppy to format and create DOS or ext2fs filesystems in a floppy.
kdm	consolekit	Enables support for authorization using consolekit
kig	kig-scripting	Support Python scripting
konqueror	auth	Add dependency on authentization packages.
	bookmarks	Add dependency on bookmark package.
	thumbnail	Enables video thumbnails generation for kde-base/konqueror file manager.
kopete	addbookmarks	Automaticaly add incoming urls to bookmarks.
	autoreplace	Automaticaly replace selected text
	bonjour	Enable Link-Local Messaging via the bonjour protocol.
	contactnotes	Enables writing personal notes for contacts.
	facebook	Enable Facebook support.
	gadu	Enable the Gadu protocol handler.
	groupwise	Enable the Groupwise protocol handler.
	highlight	Allows you to specify highlights on specific events.
	history	Enables saving chat history.
	jabber	Enable XMPP protocol handler (this is also gmail).
	latex	Embed latex formatted text into messages.
	meanwhile	Enable the Sametime protocol handler.
	msn	Enable "Windows live messenger" protocol support.
	nowlistening	Shows song you currently listen to in your status/etc. Bindings for many players.
	otr	Allows crypting your chat (drugs and talking nonsense are considered as good alternatives ;]).
	pipes	Send messages to external pipe.
	privacy	Filter for incomming messages
	qq	enable support for the chinese network protocol.
	skype	Enable Skype protocol handler (not fully functional yet).
	statistics	Everybody loves statistic graphs, especialy cake ones. ;]
	testbed	Enable the testbed protocol.
	texteffect	Various fancy text effects for your messages (dont ever consider writing us with this enabled ;]).
	translator	Translate incoming and outgoing messages.
	urlpicpreview	Enables in conversation pictures preview.
	webpresence	Show your status and some more informations on web.
	winpopup	Enable pop-up messages sending on windows. (same as good old "net send" messages ;])
	yahoo	Enable yahoo protocol support.
kpilot	avantgo	Add support for syncing Avantgo accounts
krdc	rdp	Enable runtime dependency for net-misc/rdesktop
kstars	fits	Enable support for the FITS image format through cfitsio
kstars	indi	Enable support for Astronomical control library using libindi
kttsd	epos	Build a plugin for app-accessibility/epos
	festival	Build a plugin for app-accessibility/festival
	flite	Build a plugin for app-accessibility/flite
	freetts	Build a plugin for app-accessibility/freetts
	mbrola	Build a plugin for app-accessibility/mbrola
marble	designer-plugin	Enable designer plugin
okular	chm	Enable support for Microsoft Compiled HTML Help files
	ebook	Add E-Book suppport
	ps	Add PostScript support
plasma-workspace	google-gadgets	Add google-gadgets support
plasma-workspace	rss	Enables building RSSNOW plasmoid (requires kde-base/kdepimlibs)
powerdevil	pm-utils	Adds support for suspend/resume the system through sys-power/pm-utils
pykde4	akonadi	Builds Akonadi python language bindings
smoke	akonadi	Compile bindings for kde-base/akonadi.
	kdevplatform	Compile bindings for dev-util/kdevplatform.
	phonon	Compile bindings for media-sound/phonon.
	qscintilla	Compile bindings for x11-libs/qscintilla.
	qwt	Compile bindings for x11-libs/qwt.
	webkit	Compile bindings for x11-libs/webkit.
solid	wicd	Enable Wicd wired and wireless network manager.
step	qalculate	Enable the libqalculate library for unit conversion

kde-misc

Package	Flag	Description
kdiff3	konqueror	Enable integration with konqueror
tellico	addressbook	Add support for kdepim addressbook (kabc)
tellico	xmp	Adds support for PDF/XMP metadata using media-libs/exempi

mail-client

Package	Flag	Description
alpine	chappa	enhance alpine by appling Eduardo Chappa's patches
	onlyalpine	installs only the alpine binary, so it does not collied with app-editors/pico and/or mail-client/pine
	passfile	Adds support for caching passwords into a file between sessions
	smime	Enable support for S/MIME
	topal	Enable support for net-mail/topal
balsa	crypt	Adds support for GnuPG encryption
	gtkspell	Use gtkspell for dictionary support
	rubrica	Adds support for app-office/rubrica addressbook
claws-mail	bogofilter	Build mail-filter/bogofilter plugin
	dillo	Enables support for inline HTTP email viewing with a plugin (which depends on the www-client/dillo browser)
	smime	Build plugin for S/MIME support
	spamassassin	Build mail-filter/spamassassin plugin
	ssl	Use gnutls for Secure Socket Layer transactions (deprecated, USE=gnutls should be used)
evolution	crypt	Enable GPG encryption support using app-crypt/gnupg and app-crypt/pinentry
	dbus	Allow the Mail Notification plugin to notify you about new messages via an icon in the tray using sys-apps/dbus
	exchange	Build optional Microsoft Exchange support
	hal	Enable support for auto-detection of inserted iPods and syncing data with them using sys-apps/hal
	ldap	Enable support for fetching contacts from an LDAP or Active Directory server using net-nds/openldap
	mono	Build the dev-lang/mono plugins included in Evolution
	networkmanager	Allows Evolution to automagically toggle online/offline mode by talking to net-misc/networkmanager and getting the current network state
	pda	Enable support for syncing Evolution Calendar and Addressbooks with PDAs using app-pda/gnome-pilot and app-pda/gnome-pilot-conduit
	profile	Build support for profiling Evolution for development purposes
mail-notification	gmail	Enable Gmail mailbox checking
	mh	Enable MH mailbox checking
	pop	Enable support for pop
	sylpheed	Enable support for MH mailboxes used by mail-client/sylpheed
mozilla-thunderbird	mozdom	Enable Mozilla's DOM inspector
	moznopango	Disable x11-libs/pango during runtime
	replytolist	Enable x11-plugins/replytolist plugin
mutt	gpg	Enable support for app-crypt/gpgme
	pop	Enable support for pop
	sidebar	Use the vanilla tree + sidebar patch
	smime	Enable support for smime
	smtp	Enable support for smtp
	tokyocabinet	Enable tokyocabinet database backend for header caching
nail	net	Enable network support (thus enabling POP, IMAP and SMTP)
pine	largeterminal	Add support for large terminals by doubling the size of pine's internal display buffer
pine	passfile	Adds support for caching IMAP passwords into a file between sessions
squirrelmail	filter	Enable mail-filter/amavisd-new filtering

mail-filter

Package	Flag	Description
MailScanner	bitdefender	Enable usage of bitdefender virus scanner
	exim	Set mail-mta to used MTA
	f-prot	Enable usage of app-antivirus/f-prot virus scanner
	postfix	Set mail-mta/postfix to used MTA
	spamassassin	Enable usage of mail-filter/spamassassin for spam protection
amavisd-new	courier	Add support for usage with courierfilter
	dkim	Add optional Yahoo! DomainKey support
	qmail	Add support for qmail
	razor	Configure mail-filter/razor, a distributed, collaborative spam detection and filtering network for use with amavisd-new
	spamassassin	Enable usage of mail-filter/spamassassin for spam protection
ask	procmail	Adds support for mail-filter/procmail
assp	spf	Adds support for Sender Policy Framework
assp	srs	Adds support for Sender Rewriting Scheme
bsfilter	mecab	Adds support for mecab
clamassassin	clamd	Use the app-antivirus/clamav daemon for virus checking
clamassassin	subject-rewrite	Adds support for subject rewriting
dcc	rrdtool	Enable net-analyzer/rrdtool interface scripts
dkim-milter	diffheaders	On verification failure, compare the original and the received headers to look for possible munging
dovecot-antispam	crm114	Build CRM114 backend
	dspam	Build mail-filter/dspam backend
	mailtrain	Build mailtrain backend
	signature-log	Build signature-log backend
dspam	daemon	Enable support for DSPAM to run in --daemon mode
	debug	Enable debugging support (don't enable this unless something needs testing!)
	debug-bnr	Activates debugging output for Bayesian Noise Reduction
	debug-verbose	Cause DSPAM produce verbose debug output and write them into LOGDIR/dspam.debug file. Never enable this for production builds!
	large-domain	Builds for large domain rather than for domain scale
	user-homedirs	uild with user homedir support
	virtual-users	Build with virtual-users support
libmilter	poll	Use poll instead of select
maildrop	authlib	Add courier-authlib support
mimedefang	poll	Use poll instead of select
opendkim	asyncdns	Use inbuilt asynchronous DNS library for queries
	db	Include features like stats, querycache, popauth, report intervals and bodylengthdb that include berkdb
	diffheaders	On verification failure, compare the original and the received headers to look for possible munging
	multiplesigs	Allow addition of multiple signatures when key lists are in use.
postgrey	targrey	Enables the targrey patch
qmail-scanner	spamassassin	Build faster mail-filter/spamassassin checks into qmail-scanner
simscan	attachment	Enable attachment scanning
	custom-smtp-reject	Return smtp reject message with virus name
	dropmsg	Drop message in case of virus/spam
	passthru	Passthru message in case of virus/spam
	per-domain	Enable support for per-domain settings
	quarantine	Enable quarantine support
	received	Add Received: line to mail headers
	regex	Enable regular expression matching
	spam-auth-user	Turn on spam scanning for authenticated users
	spamassassin	Use mail-filter/spamassassin for spam checking
	spamc-user	Set user option to spamc
spamassassin	qmail	Build qmail functionality and docs
spamassassin	tools	Enables tools for spamassassin
spamassassin-fuzzyocr	amavis	Enable support for mail-filter/amavisd-new
	gocr	Enable support for the gocr OCR engine
	logrotate	Install support files for app-admin/logrotate
	ocrad	Enable support for the ocrad OCR engine
	tesseract	Enable support for the tesseract OCR engine
spamdyke	tls	Enables TLS protocol for spamdyke

mail-mta

Package	Flag	Description
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	dnsdb	Adds support for a DNS search for a record whose domain name is the supplied query
	domainkeys	Adds support for Yahoo!'s DomainKey sender verification system
	dovecot-sasl	Adds support for Dovecot's authentication
	exiscan	Patch providing support for content scanning backward-compatibility
	exiscan-acl	Patch providing support for content scanning
	lmtp	Adds support for lmtp
	mbx	Adds support for UW's mbx format
	spf	Adds support for Sender Policy Framework
	srs	Adds support for Sender Rewriting Scheme
netqmail	authcram	Enable AUTHCRAM support
	gencertdaily	Generate SSL certificates daily instead of hourly
	highvolume	Prepare netqmail for high volume servers
	noauthcram	If you do NOT want AUTHCRAM to be available
postfix	dovecot-sasl	Enable net-mail/dovecot protocol version 1 (server only) SASL implementation
postfix	vda	Adds support for virtual delivery agent quota enforcing
qmail-ldap	cluster	Enable this if you want to have cluster support in qmail-ldap
	gencertdaily	Generate SSL certificates daily instead of hourly
	highvolume	Prepare qmail for high volume servers
	rfc2307	Add support for RFC2307 compliant uid/gid attributes
	rfc822	Add support for RFC822 compliant mail attributes
qpsmtpd	async	Add deps + support for asynchronous mail reception/processing as well as preforked daemon
qpsmtpd	postfix	create user with permissions for proper postfix interaction
ssmtp	maxsysuid	Allow to define a MinUserId
ssmtp	md5sum	Enables MD5 summing for ssmtp

media-fonts

Package	Flag	Description
culmus-ancient	fontforge	Use media-gfx/fontforge to build fonts from source
dejavu	fontforge	Use media-gfx/fontforge to build fonts from source
intlfonts	bdf	Installs BDF fonts in addition to PCF
mplus-outline-fonts	ipafont	Generates new fonts merged with media-fonts/ja-ipafonts
sil-charis	compact	Use more compactly spaced font
terminus-font	a-like-o	Changes view of letter 'a' - a looks like o (see homepage)
	bolddiag	Boldified diagonal parts of '4', 'k', 'x' and some other chars
	pcf	Intall Portable Compiled Font (PCF) (required for X11)
	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)
	raw-font-data	Install RAW font data which should be compatible with most UNIX systems (you don't need this on linux)
	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)
	width	Wider versions of some font elements

media-gfx

Package	Flag	Description
album	plugins	Install optional plugins
album	themes	Install optional themes
asymptote	boehm-gc	Enables using the Boehm-Demers-Weiser conservative garbage collector
asymptote	sigsegv	Enables using dev-libs/libsigsegv
blender	blender-game	Adds game engine support to blender
	player	Enable blender player
	verse	Adds verse clustering features to blender
comix	rar	Pulls app-arch/unrar for rar file support
digikam	addressbook	Add support for kdepim
	geolocation	Add support for marble
	lensfun	Enable support for lens-correnction library
	thumbnails	Allow thumbnail previews for images/photos
eog	xmp	Adds support for XMP metadata
exiv2	contrib	Build additional contrib components
exiv2	xmp	Adds support for Adobe XMP
f-spot	beagle	Enable app-misc/beagle support for searches
f-spot	flickr	Enable building of the Flickr exported.
fontforge	cjk	Controls whether fontforge understands the gb12345 encoding and installs cidmap package to edit CID-keyed fonts
	pango	Enable pango font rendering
	pasteafter	Controls whether fontforge has a paste after command (Useful for making words?). This is kind of fun, but it isn't useful for normal fonts.
	tilepath	Controls whether fontforge has a tile path command (a variant of expand stroke) This is useful for very decorative fonts, most people won't want it.
	truetype-debugger	Enable truetype debugger in fontforge
	type3	Build in support for type3/svg fonts containing multilayered drawing with strokes, fills, images, etc. Type3 fonts are only supported by postscript printers (not by most windowing displays). They are capable of more exotic images than normal fonts but require much more effort to support.
freewrl	libeai	Build EAI C library
freewrl	spidermonkey	Use spidermonkey instead of Firefox
geeqie	xmp	Adds support for XMP metadata
gimp	smp	Enable support for multiprocessors
gimp	webkit	Enable the webkit rendering engine
graphviz	cgraph	Enables cgraph (PostScript plotting library in C) library
	lasi	Enables PostScript output via media-libs/lasi library
	pango	Enables the rendering of the graphs using pango & cairo (with antialiasing support)
gthumb	iptc	Add support for IPTC metadata
hugin	sift	automatically align images with media-gfx/autopano-sift or media-gfx/autopano-sift-C
imagemagick	autotrace	use media-gfx/autotrace to convert bitmaps into vector graphics
	corefonts	pull in media-fonts/corefonts, which is required for some commands
	fpx	enable media-libs/libfpx support
	gs	enable ghostscript support
	hdri	enable High Dynamic Range Images formats
	lqr	enable experimental liquid rescale support
	q32	set quantum depth to 32
	q8	set quantum depth to 8
inkscape	dia	pull in app-office/dia for dia import extension
	inkjar	enables support for OpenOffice.org SVG jar files
	postscript	pull in dependencies needed for the postscript import extension
	wpg	build with media-libs/libwpg support (C++ library to read and parse graphics in WPG)
jpeg2ps	metric	Default to A4 paper size
k3d	3ds	Enable support for 3D Studio models
	cuda	Use nvidia cuda toolkit for speeding up computations
	gts	Add Support for the GNU Triangulated Surface Library sci-libs/gts
	plib	build plib-based import/export library
kphotoalbum	geolocation	Add support for kde-base/marble
kphotoalbum	kipi	Support for the KDE Image Plugin Interface
maya	bundled-libs	Use the bundled versions of libs rather than system ones (libstdc++, libgcc_s, libqt, and libXm)
maya	maya-shaderlibrary	Install the maya shader library
openclipart	gzip	Compresses clip art using gzip
potrace	metric	default to a4 paper size and metric measurement
pstoedit	emf	enables media-libs/libemf support
splashutils	fbcondecor	Support for the fbcondecor kernel patch.
ufraw	contrast	enable contrast setting option
	hotpixels	enable hot pixel elimination
	lensfun	enable the lensfun lens-correction library
	timezone	enable DST correction for file timestamps
yafaray	blender	install media-gfx/blender scripts

media-libs

Package	Flag	Description
a52dec	djbfft	Prefer D.J. Bernstein's library for fourier transforms
allegro	vga	Enables the VGA graphics driver
alsa-lib	alisp	Enable support for ALISP (ALSA LISP) interpreter for advanced features.
cal3d	16bit-indices	Enables use of 16bit indices
devil	allegro	Add support for Allegro
esdl	image	Enable image support
faad2	digitalradio	Digital Radio Mondiale (warning: disables other decoders)
freetype	fontforge	Install internal headers required for truetype debugger in media-gfx/fontforge (built with USE=truetype-debugger)
	kpathsea	Enable TeX support (ttf2pk and ttf2pfb)
	utils	Install utilities and examples from ft2demos
freeverb3	audacious	Build Audacious plugin
	forcefpu	Disable assembly code
	plugdouble	Build plugins in double precision mode (default is float)
giflib	rle	Build converters for RLE format (utah raster toolkit)
glide-v3	voodoo1	Support 3DFX Voodoo1 video cards
	voodoo2	Support 3DFX Voodoo2 video cards
	voodoo5	Support 3DFX Voodoo4 and Voodoo5 video cards
libass	enca	Enables support for charset discovery and conversion.
libcanberra	alsa	Enables ALSA sound driver.
	gstreamer	Enables gstreamer sound driver. Not useful when alsa or pulseaudio is available.
	gtk	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.
	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.
libdc1394	juju	Use the new juju firewire stack in the Linux kernel
libggi	vis	Enables sparc vis support for libggi
libgphoto2	bonjour	Adds Bonjour/Zeroconf support.
libgpod	gtk	Enables ArtWorkDB support (including Photos and album covers)
libmp4v2	utils	Install command-line utilities
libquicktime	schroedinger	Enable Dirac video support (an advanced royalty-free video compression format) via libschroedinger (high-speed implementation in C of the Dirac codec).
libsdl	audio	Control audio support (disable at your own risk)
	joystick	Control joystick support (disable at your own risk)
	ps3	Build the PS3 video driver
	tslib	Build with tslib support for touchscreen devices
	video	Control video support (disable at your own risk)
libvorbis	aotuv	Applies the aoTuV patches. Aoyumi's Tuned Vorbis is a third-party patchset that improves the vorbis encoding quality. A previous version of the aoTuV patchset has already been merged with the official libvorbis release. The current patchset especially improves encoding quality at low bitrate settings, and is very likely to be merged at some point in the future. It is recommended that all users enable this useflag.
mediastreamer	ilbc	Use of iLBC (RFC3951) codec plugin
mediastreamer	video	Enable video support
mesa	pic	disable optimized assembly code that is not PIC friendly
mlt	compressed-lumas	Compress the luma files in png.
	frei0r	Build the module for media-plugins/frei0r-plugins
	melt	Build the melt commandline tool
netpbm	rle	Build converters for the RLE format (utah raster toolkit)
opencv	deprecated	Enable deprecated (old) python support
	ipp	Enable Intel Integrated Primitive support
	octave	Enable octave support
	sse3	Enable optimization for SSE3 capable chips
openjpeg	tools	Installs tools (j2k_to_image and image_to_j2k)
panda3d	fmod	Enables support for using mod files for audio support
panda3d	nspr	Enables support for the Netscape Portable Runtime, used in network interface functionality (ie. multiplayer online game networking).
ploticus	cpulimit	Limit cpu usage when generating graphics
	flash	Adds support for creating SWF files using Ming
	svgz	Compressed svg graphics support
sdif	ftruncate	Enables usage of ftruncate v. truncate
sdl-mixer	midi	basic support for MIDI files
sdl-mixer	wav	support WAVE files
sdl-sound	physfs	Enable physfs support
sge	image	enable sdl-image support
spandsp	fixed-point	Enable fixed point support
	sse3	Enable SSE3 support
	sse4	Enable SSE4 support
	sse4a	Enable SSE4a support
	sse5	Enable SSE5 support
svgalib	kernel-helper	Build the helper kernel module
swfdec	alsa	Use ALSA for audio output
	doc	Build documentation
	ffmpeg	Use media-plugins/gst-plugins-ffmpeg to enable Flash video support. Necessary if you want to use sites like youtube
	gstreamer	Enable media-libs/gstreamer to support various media input formats. i.e. audio (mp3) and video (flv)
	gtk	Enable GTK+ convenience library while is necessary for all GTK+ apps using swfdec (gnome-extra/swfdec-gnome and www-plugins/swfdec-mozilla)
	oss	Use Open Sound System for audio output
	pulseaudio	Use media-sound/pulseaudio for audio output
taglib	asf	Provide support for Microsoft's 'advanced systems format' media container.
urt	gs	Add support for postscript
win32codecs	real	Installs the real video codecs
x264	pic	disable optimized assembly code that is not PIC friendly
xine-lib	dxr3	Enable support for DXR3 mpeg accelleration 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.
	gnome	Build the gnome-base/gnome-vfs based input plugin. This plugin is used to access any resource that can be accessed through Nautilus's (and others') URLs.
	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.
	real	Enable support for loading and using RealPlayer binary codecs on x86 and amd64 Linux. Enabling this USE flag might make the package non-redistributable in binary form.
	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.
	vidix	Enable support for vidix video output.
	vis	Adds support for SIMD optimizations for UltraSPARC processors.
	win32codecs	Enable support for loading and using Windows 32-bit binary codecs on x86 Linux and FreeBSD. Enabling this USE flag might make the package non-redistributable in binary form.
	xvmc	Enable support for XVideo Motion Compensation (accelerated mpeg playback).
xvid	pic	disable optimized assembly code that is not PIC friendly

media-plugins

Package	Flag	Description
audacious-plugins	adplug	Build with AdPlug (Adlib sound card emulation) support
	bs2b	Enable Bauer Bauer stereophonic-to-binaural headphone filter
	chardet	Try to handle non-UTF8 chinese/japanese/korean ID3 tags
	cue	Support CUE sheets using the libcue library
	icecast	Support for Icecast2 streaming
	projectm	Build with ProjectM visualization
	scrobbler	Build with scrobbler/LastFM submission support
	sid	Build with SID (Commodore 64 Audio) support
	tta	Build with TTA (True-Audio Loseless) support
	wma	Build with WMA (Windows Media Audio) support
frei0r-plugins	facedetect	Enables building of facedetect plugin, which depends on media-libs/opencv
frei0r-plugins	scale0tilt	Enables building of scale0tilt and vectorscope plugins, which depend on media-libs/gavl
gkrellmpc	threads	Use separate thread to init connection (unsafe)
gst-plugins-meta	mythtv	Support for retrieval from media-tv/mythtv backend
kipi-plugins	linguas_zn_CN	Add zn_CN lingua suppport
	mjpeg	Add mjpeg suppport
	redeyes	Add redeyes removal suppport
mythmusic	libvisual	Enables media-libs/libvisual support for effects
mythphone	festival	Enable app-accessibility/festival support
mythvideo	jamu	Use and configure the Just Another Metadata Utility by default
mythzoneminder	minimal	Don't build the mythtv side of this plugin, only the part that communicates with zoneminder.
vdr-burn	projectx	Enables support for media-video/projectx
vdr-dvdconvert	projectx	Enable support for media-video/projectx
vdr-epgsearch	tre	Add support for unlimited fuzzy searching with help of dev-libs/tre library
vdr-graphtft	graphtft-fe	Install external x11 remote frontend
	theme_avp	graphTFT Alien vs. Predato theme
	theme_deepblue	graphTFT default theme
	theme_deeppurple	graphTFT Deep Purple theme
	theme_poetter	graphTFT Poetter theme
	touchscreen	Enable Touchscreen support
vdr-music	4mb-mod	Enables support for modded FF-Card to 4MB ram or softdecoder
	ff-card	Enables scrollmode on FF-Card
	graphtft	Enable support for media-plugins/vdr-graphtft
vdr-pvr350	yaepg	Enables full support for the output format of media-plugins/vdr-yaepg
vdr-softdevice	mmxext	enables MMXExt support
vdr-streamdev	client	Compile the VDR plugin vdr-streamdev-client that acts like a dvb-budget card
vdr-streamdev	server	Compile the VDR plugin vdr-streamdev-server that allows remote systems to access the DVB cards used for the local VDR
vdr-text2skin	direct_blit	not buffer picture, faster, but only for modified skins
vdr-weatherng	dxr3	enables lower osd color depth for dxr3 cards
vdr-xineliboutput	libextractor	Use media-libs/libextract to gather files' metadata in media-player
	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

Package	Flag	Description
tucnak2	ftdi	Enable support for FTDI USB chips
tucnak2	hamlib	Enables support by the Hamlib amateur radio rig control library to get/set frequency and mode of the ham radio

media-sound

Package	Flag	Description
abcde	id3	Support ID3, ID3v2 tagging of audio files
	normalize	Add support for normalizing audio file volume levels
	replaygain	Support for Replay Gain metadata, for relative volume adjustment
alsa-tools	midi	Build the sequencer (midi) utilities
alsaplayer	id3tag	Enables ID3 tagging with id3tag library
amarok	amazon	Enable support for downloading covers from amazon.com
	daap	Enable the scripts for music sharing through DAAP. This flag adds dependencies on www-servers/mongrel to allow sharing of the Amarok music collection through DAAP protocol. Please note that turning this flag off has no effect on DAAP browsing.
	ifp	Enable support for iRiver devices access through libifp
	lastfm	Enable Last.fm streaming services support through media-libs/liblastfm
	mp3tunes	Enable mp3tunes integration
	mp4	Build the TagLib plugin for writing tags in Mp4 container files (m4a). Please note that by enabling this USE flag, the resulting package will not be redistributable, as it links to media-libs/libmp4v2, distributed under a GPL-incompatible license.
	njb	Enable support for NJB (Creative) devices access through libnjb
	python	Install the Amarok scripts written in Python, depending on dev-python/PyQt. At the moment the only script installed by this flag is the webcontrol script.
	real	Build the Helix engine for Amarok, linked against media-video/realplayer. This is an alternative engine to the xine one, which supports a different set of formats. Only available for x86 architecture as it uses the binary version of RealPlayer. Please note that by enabling this USE flag, the resulting package will not be redistributable, as it links to the non-GPL compatible RealPlayer.
	visualization	Support visualization plugins through media-libs/libvisual
aqualung	ifp	Enable support for iRiver iFP portable audio players
	lua	Enable support for programmable title formatting with dev-lang/lua
	podcast	Enable podcast support
	systray	Enable system tray support
ardour	freesound	Enables direct searching and download of samples from Freesound via the Import dialog
ardour	lv2	Add support for Ladspa V2
ario	audioscrobbler	Enable song tracking via last.fm
ario	idle	Enable experimental support for MPD's idle command to reduce bandwith and cpu usage, requires MPD 0.14
audacious	chardet	Try to handle non-UTF8 chinese/japanese/korean ID3 tags
audacity	id3tag	Enables ID3 tagging with id3tag library
	midi	Enables MIDI support
	soundtouch	Enables soundtouch library support
	twolame	Enables twolame support (MPEG Audio Layer 2 encoder)
	vamp	Enables vamp plugins support (Audio analysing plugins)
banshee	boo	Use external Boo instead of the bundled one
	daap	Build with Daap support
	karma	Build with karma support
	podcast	Build with podcasting support
cmus	pidgin	install support script for net-im/pidgin
	wma	add support for Windows Media Audio
	zsh-completion	enable zsh completion support
darkice	twolame	Build with twolame support
decibel-audio-player	gnome-keyring	Adds support for storing your Last.fm password using gnome-keyring.
dir2ogg	wma	Add support for wma files through mplayer
exaile	libsexy	Enable libsexy support
fapg	xspf	Enable support for saving XSPF playlists.
freewheeling	fluidsynth	compile with support for fluidsynth
gejengel	audioscrobbler	Enable track submission on last.fm
gimmix	cover	Enable cover art fetching
gimmix	lyrics	Enable lyric fetching
gmpc	xspf	Enable support for reading and saving XSPF playlists
gmusicbrowser	webkit	Enables gtk WebKit support
herrie	http	Enable http streaming
herrie	xspf	Enable support for reading and saving XSPF playlists
jack-audio-connection-kit	coreaudio	Build the CoreAudio driver on Mac OS X systems
	cpudetection	Enables runtime cpudetection
	netjack	Build with support for Realtime Audio Transport over generic IP
lame	mp3rtp	Build the mp3-to-RTP streaming utility. UNSUPPORTED
listen	libsexy	Enable libsexy support
listen	webkit	Enable webkit rendering engine instead of mozembed
lmms	fluidsynth	Enables Fluidsynth MIDI software synthesis plugin.
	stk	Enables STK Mallet plugin.
	vst	Enables the VeSTige plugin to run VST plugins through Wine.
mixxx	djconsole	Enable djconsole support
	hifieq	Enable hifi equalizer support
	recording	Enable experimental recording support
	shout	Enable shoutcast support
	vinylcontrol	Enable vinylcontrol feature
moc	sid	Build with SID (Commodore 64 Audio) support
mp3blaster	sid	Build with SID (Commodore 64 Audio) support
mp3splt-gtk	audacious	Include media-sound/audacious support
mpd	cdio	Use libcdio for ISO9660 parsing support
	cue	Support CUE Sheet Parser Library
	curl	Support for web stream listening
	fifo	Support writing audio to a FIFO
	fluidsynth	Enables Fluidsynth MIDI software synthesis
	id3	Support for ID3 tags
	lame	Support for MP3 streaming via Icecast2
	lastfmradio	Support listening to last.fm radio stations
	libmms	Support for Microsoft Media Server (MMS) streams via libmms
	network	Enables network streaming support
	pipe	Support writing audio to a pipe
	sid	Build with SID (Commodore 64 Audio) support
	zip	Support for ZIP files
mpfc	wav	Enable wav audio codec support
mpg123	3dnowext	Enable 3dnowext cpu instructions
mpg123	network	Enable network support (http streams / webradio)
mumble	g15	Enable support for the Logitech G15 LCD (and compatible devices).
mumble	speech	Enable text-to-speech support in Mumble.
murmur	ice	Use dev-cpp/Ice to enable remote control capabilities.
ncmpc	artist-screen	Enable artist screen
	colors	Enable color support
	help-screen	Enable the help screen
	key-screen	Enable key editor screen
	lyrics-screen	Enable lyrics screen
	mouse	Enable curses getmouse support
	search-screen	Enable search screen
	song-screen	Enable song viewer screen
ncmpcpp	clock	Enable clock screen
	fftw	Build the visualizer plugin that pulls in sci-libs/fftw
	outputs	Enable outputs screen
	visualizer	Enable visualizer screen with sound wave/frequency spectrum modes
podcatcher	bittorrent	Enable support for bittorrent downloads
pulseaudio	X	Build the X11 publish module to export PulseAudio information through X11 protocol for clients to make use. Don't enable this flag if you want to use a system wide instance. If unsure, enable this flag.
	asyncns	Use libasyncns for asynchronous name resolution.
	doc	Build the doxygen-described API documentation.
	glib	Enable glib eventloop support
	gnome	Use GConf to store user preferences on streams and so on. Don't enable this flag if you want to use a system wide instance. If unsure, enable this flag.
	oss	Enable OSS sink/source (output/input). Deprecated, upstream does not support this on systems where other sink/source systems are available (i.e.: Linux). The padsp wrapper is now always build if the system supports OSS at all.
	udev	Use sys-fs/udev for autodiscovery of sound devices; this replaces the deprecated sys-apps/hal autodiscovery code.
qmmp	bs2b	Enable Bauer stereophonic-to-binaural headphone filter
	projectm	Enable projectm music visualization plugin
	scrobbler	Enable audioscrobbler/last.fm support
qsampler	libgig	Enable libgig support for loading Gigasampler files and DLS (Downloadable Sounds) Level 1/2 files
qtractor	dssi	Enable support for DSSI Soft Synth Interface
qtractor	rubberband	Enable support for in-place audio clip pitch-shifting through the rubberband library
qtscrobbler	cli	Build commandline client
quodlibet	trayicon	Enable support for trayicon
	tta	Enable TTA (True-Audio Loseless) support
	wma	Enable support for Windows Media Audio
radiomixer	hwmixer	Use hardware mixer instead of internal mixer routines
rezound	16bittmp	Use 16bit temporary files (default 32bit float), useful for slower computers
rezound	soundtouch	compile with support for soundtouch
rhythmbox	brasero	Enable CD burning via app-cdr/brasero rather than gnome-extra/nautilus-cd-burner
	daap	Enable support for local network music sharing via daap
	udev	Enable hardware detection via sys-fs/udev replacing the deprecated sys-apps/hal code.
rosegarden	dssi	Enable support for DSSI Soft Synth Interface
rubyripper	cli	Build command line interface rubyripper
	normalize	Add support for normalizing audio file volume levels
	wav	Add support for wavegain
sonata	lyrics	Support for lyrics fetching
sonata	trayicon	Enable support for trayicon
sonic-visualiser	id3tag	Enables ID3 tagging with id3tag library
sox	id3tag	Enables ID3 tagging with id3tag library
squeezecenter	aac	Enable playback support for AAC (.m4a) encoded files
	alac	Enable support for alac
	bonjour	Enable support for bonjour
traverso	lv2	Add support for Ladspa V2
vorbis-tools	ogg123	Build ogg123 player, needs libao and curl
xwax	alsa	Enable ALSA support.

media-tv

Package	Flag	Description
freevo	ivtv	Enables ivtv support
	mixer	Enable support for adjusting volume via media-sound/aumix
	snes	Enable Super Nintendo games support
	tv	Enable support for the tv guide plugin
	tvtime	Enables tvtime support, additional to tv use flag
	xmame	Enables support for Xmame arcade games
gentoo-vdr-scripts	nvram	Add support for using nvram-wakeup to set wakeup time in bios
kdetv	zvbi	Enable VBI Decoding Library for Zapping
mythtv	alsa	Allows MythTV to directly output sound to ALSA devices, this is needed if you are using ALSA dmix or SPDIF. Note, you will have to physically type your device into the MythTV configuration since it will only give you /dev/dsp devices in the drop down.
	altivec	Builds ffmpeg's codec libraries with altivec support.
	autostart	Uses a custom autostart configuration gleened from expierence with MythTV since it's early versions and discussed with other MythTV maintainers and users. Does not rely on KDE being installed like most methods do.
	debug	Instructs Qt to use the 'debug' target instead of 'release' target. If your MythTV is crashing or you need a backtrace, you need to compile it with this option otherwise the debugging data is useless.
	directv	Installs the DirecTV channel changing script so that you can configure MythTV to use it to change the channels on your DirecTV box.
	dvb	Enables support for Linux DVB cards. These include all cards that work with digital signals such as ATSC, DVB-T, DVB-C, and DVB-S, QAM-64, and QAM-256.
	faad	Uses external faad library for AAC decoding instead of internal libavcodec for decoding AAC. The faad library supports additional AAC types like AAC-LATM that libavcodec does not support
	ieee1394	Allows MythTV to communicate and use Firewire enabled Cable boxes. These are typically found in the United States, where such support is required by law. This will also install Firewire test programs and external channel changers if the internal changer does not work.
	jack	Allows MythTV to use JACK as your sound output device. You will have to manually configure the path to your JACK settings.
	lcd	Tells MythTV that you have an instance of app-misc/lcdproc configured on your machine and it should output information such as current time, show name, episode name, etc to that LCD.
	lirc	Adds LIRC support directly to MythTV allowing for built in control via a LIRC device.
	mmx	Builds ffmpeg's codec libraries with mmx support.
	opengl	Builds MythTV with support for using OpenGL as the output painter rather then Qt3 built in painter.
	perl	Builds the perl bindings for MythTV. Allows you to write scripts in Perl to control your MythTV setup or communicate with it.
	tiff	Add support for tiff loading and rendering which is only used by media-plugins/mythgallery
	vdpau	enable support of NVIDIA's VDPAU for video playback
	video_cards_nvidia	When combined with the xvmc USE flag, enables NVIDIA specific XvMC extension usage.
	xvmc	Instructs MythTV to use XvMC for it's video output. By default, this will use the generic XvMC wrapper unless a specific video card driver is enabled via their VIDEO_CARDS USE flags.
tvbrowser	themes	Install extra theme packs
xawtv	xext	Enable use of XFree extensions (DGA,VidMode,DPMS)
xawtv	zvbi	Enable VBI Decoding Library for Zapping
xbmc	vdpau	enable support for Video Decode and Presentation API for Unix
xdtv	aqua_theme	Enable graphic theme Aqua-style
	carbone_theme	Adds the Carbone pixmaps theme for the GUI
	schedule	Adds the possibility to schedule tv recording via xdtv_record.sh
	zvbi	Enable VBI Decoding Library for Zapping
xmltv	ar	Argentina tv listing grabber
	be	Belgium and Luxemburg tv listing grabber
	brnet	Brazil cable tv listing grabber
	ch	Switzerland bluewin tv listing grabber
	dk	Denmark tv listing grabber
	dtvla	Latin America digital tv listing grabber
	ee	Estonia tv listing grabber
	es	Spain tv listing grabber
	es_laguiatv	Spain alternative grabber
	es_miguiatv	Spain alternative grabber
	eu_epg	EPG grabber for some European countries.
	fi	Finland tv listing grabber
	fr	France tv listing grabber
	hr	Croatia tv listing grabber
	huro	Hungarian tv listing grabber
	is	Iceland tv listing grabber
	it	Italy tv listing grabber
	jp	Japan tv listing grabber
	na_dd	North America tv listing grabber
	na_dtv	North America Direct TV grabber
	na_icons	option for na_dd to download icons
	nc	Caledonie Island tv listing grabber
	nl	Netherlands tv listing grabber
	nl_wolf	Netherlands alternative tv listing grabber
	no	Norway tv listing grabber
	no_gf	Norway Gfeed tv listing grabber
	pt	Portugal tv listing grabber
	re	Reunion Island (France) tv listing grabber
	se_swedb	Sweden tv listing grabber
	tv_check	enable GUI checking
	tv_combiner	enable grabbers combiner
	tv_pick_cgi	enable CGI support
	uk_bleb	Britain tv listing grabber
	uk_rt	Britain alternative tv listing grabber
	za	South Africa tv listing grabber

media-video

Package	Flag	Description
arista	faac	Use external faac library for AAC encoding
avidemux	aften	Enable A/52 (AC-3) audio encoder support
avidemux	amr	Enable Adaptive Multi-Rate format support through media-libs/opencore-amr
chaplin	transcode	Enable DVD ripping and transcoding
cinepaint	gutenprint	Enable support for gutenprint
clive	clipboard	Support reading from X clipboard
	pager	Support pager!?
	password	Support password controlled sites
devede	psyco	psyco python accelerator
dv2sub	kino	install kino plugin
dvd-slideshow	themes	Install theme pack
dvdrip	fping	Enables fping support for cluster rendering
dvdrip	subtitles	Enables support for subtitle ripping
ffmpeg	3dnowext	Enable manually-optimised routines using the AMD 3DNow!Ex SIMD instruction set, present in modern AMD CPUs. (Check for 3dnowext in /proc/cpuinfo to know whehter you support it).
	amr	Enables Adaptive Multi-Rate Audio support
	cpudetection	Enables runtime cpudetection (useful for bindist, compatability on other CPUs)
	dirac	Enable Dirac video support (an advanced royalty-free video compression format) via the reference library: dirac.
	faac	Use external faac library for AAC encoding
	faad	Use external faad library for AAC decoding (instead of internal libavcodec support)
	hardcoded-tables	Use pre-calculated tables rather than calculating them on the fly.
	mmxext	Enables mmx2 support
	network	Enables network streaming support
	opencore-amr	Enables Adaptive Multi-Rate format support
	pic	Force shared libraries to be built as PIC (this is slower)
	schroedinger	Enable Dirac video support (an advanced royalty-free video compression format) via libschroedinger (high-speed implementation in C of the Dirac codec).
	ssse3	faster floating point optimization for SSSE3 capable chips (Intel Core 2 and later chips)
	vdpau	Enables VDPAU decoders (requires nVidia video cards to offload CPU processing to video card
	vhook	Enables video hooking support.
ffmpeg2theora	kate	Adds support for Ogg Kate subtitles via libkate.
ffprobe	perl	Installs tools written in perl to produce plots based on video frame bitrate and size
gpac	amr	Adaptive Multi-Rate Audio support (commonly used in telephony)
griffith	csv	Enable proper support for csv import (respectively auto-detection encoding of csv files)
h264enc	ogm	Support for OGM container format
kino	gpac	Enable GPAC support when exporting to 3GPP format
kmplayer	npp	Compile the npp backend that plays xembed style browser plugins.
lives	libvisual	Enable libvisual support
mjpegtools	yv12	Enables support for the YV12 pixel format
motiontrack	multiprocess	Enables multi-process support (SMP/cluster) for motiontrack programs
mplayer	3dnowext	Enable 3dnowext cpu instructions
	ass	Internal SRT/SSA/ASS (SubRip / SubStation Alpha) subtitle support
	bl	Enables Blinkenlights support in mplayer
	bs2b	Enable Bauer stereophonic-to-binaural headphone filter
	cdio	Use libcdio for CD support (instead of cdparanoia)
	cpudetection	Enables runtime cpudetection (useful for bindist, compatability on other CPUs)
	custom-cpuopts	Fine-tune custom CPU optimizations (UNSUPPORTED)
	dirac	Enable Dirac video support (an advanced royalty-free video compression format) via the reference library: dirac.
	dvdnav	Use forked libdvdnav, navigate menus in GUIs
	dxr3	Enable DXR3/H+ video output
	enca	Enables support for charset discovery and conversion
	external-ffmpeg	Use shared FFmpeg libraries instead of static bundled ones. Discouraged by upstream.
	faac	Use external faac library for AAC encoding
	faad	Use external faad library for AAC decoding
	gmplayer	Build gmplayer, a GTK+ MPlayer gui (UNSUPPORTED)
	gtk	Build gmplayer, a GTK+ MPlayer gui (UNSUPPORTED)
	live	Enables live.com streaming media support
	md5sum	Enables md5sum video output
	mmxext	Enables mmx2 support
	mng	MNG input support
	mp2	Enables support for twolame, an MP2 audio library
	nemesi	Enable Nemesi Streaming Media support
	network	Enables network streaming support
	nut	Enables support for the NUT container format
	opencore-amr	Enables Adaptive Multi-Rate format support
	osdmenu	Enables support for on-screen display (OSD) menus
	pnm	Add PNM video output option, to create PPM/PGM/PGMYUV images
	pvr	Enable Video4Linux2 MPEG PVR
	radio	Enable V4L2 radio interface and support
	rar	Enable Unique RAR File Library
	real	Adds real audo/video support
	rtc	Enables usage of the linux real time clock. The alternative is software emulation of rtc
	schroedinger	Enable Dirac video support (an advanced royalty-free video compression format) via libschroedinger (high-speed implementation in C of the Dirac codec).
	shm	Enable support for shm
	ssse3	faster floating point optimization for SSSE3 capable chips (Intel Core 2 and later chips)
	teletext	Support for TV teletext interface
	tga	Enables Targa video output
	toolame	Enable toolame MPEG-2 encoding
	tremor	Enable internal support for Vorbis
	twolame	Enable twolame MPEG-2 encoding
	vdpau	Enables experimental VDPAU support (requires nVidia video cards) to offload MPEG2/MPEG4/VC1/WMV CPU processing to video card
	vidix	Support for vidix video output
	xanim	Enables support for xanim based codecs
	xvmc	Enables X-Video Motion Compensation support
	zoran	Enables ZR360[56]7/ZR36060 video output
ogmrip	ogm	Support for OGM container format
ogmrip	srt	Support for SRT subtitle format
qdvdauthor	plugins	Install additional plugins.
qdvdauthor	templates	Install various templates.
totem	bluetooth	Enable support for user-presence detection via the user's bluetooth handset using net-wireless/bluez-libs
	galago	Enable the galago plugin
	iplayer	Enable BBC player support
	lirc	Enable support for controlling Totem with a remote control using app-misc/lirc
	nautilus	Enable the nautilus extension
	nvtv	Support for nvtv to use tv in on nvidia cards
	python	Build support for dev-lang/python plugins
	seamonkey	same as nsplugin description but build against www-client/seamonkey
	tracker	Enable the search plugin using app-misc/tracker
	xulrunner	same as nsplugin description but build against net-libs/xulrunner
	youtube	Enable youtube plugin
transcode	extrafilters	Install some filters only if we ask for them
	fame	Enables libfame support
	mjpeg	Enables mjpegtools support
	network	Enables network streaming support
	nuv	NuppelVideo container format demuxing
	postproc	Build with ffmpeg libpostproc support
undvd	ogm	Support for OGM container format
vdr	aio	Use "all in one" patch (or its successor "liemikuutio") with much additional features
	analogtv	Add support for the analogtv plugin
	atsc	Support for NorthAmerican Broadcast ( rudimentary )
	bigpatch	Enables almost all additional features flying around on the net (including aio)
	child-protection	Enable support for the plugin vdr-pin (Protecting some recordings / channels with a PIN)
	cmdctrl	allows switching remote control on/off
	cmdreccmdi18n	loads translated commands and reccommands files if existing
	cmdsubmenu	Allows the creation of submenus in the commands menu
	cutterlimit	Limit IO bandwith used for cutting
	cutterqueue	Adds a queue of recordings to be cutted
	cuttime	Adjust starttime of cutted recording by length of cut out parts
	ddepgentry	remove duplicate EPG entries
	deltimeshiftrec	Auto delete timeshift recordings
	dolby-record-switch	Allows to control separately to record / to replay dolby digital
	dolbyinrec	add a dedicated switch to control recording of dolby digital
	dvbplayer	Use some special mpeg-repacker features. Most usable for old recordings or software output devices.
	dvbsetup	Setup for AC3 transfer, disable primary tuner
	dvdarchive	DMH DVD - Archiv ( used by vdr-burn-0.1.0_* )
	dvdchapjump	Jump on capitels on DMH DVD - Archiv
	dvlfriendlyfnames	filter file names on recording
	dvlrecscriptaddon	enhancement for record-script
	dvlvidprefer	controls video-dir choice on recording
	dxr3	Enable tweaks to improve vdr behaviour on dxr3-cards
	dxr3-audio-denoise	Mutes audio noise occurring with dxr3-cards using analog audio-out when e.g. cutting
	em84xx	Add support for em84xx plugin
	graphtft	support for grapftft plugin up from vdr-graphtft-0.1.7
	hardlinkcutter	Speed up cutting by hardlinking unchanged files
	iptv	Enables channel parameters for vdr-iptv and other input plugins
	jumpplay	Enables automatic jumping over cut marks while watching a recording
	liemikuutio	Formerly known as AIO (all-in-one) patch, adds some nice must haves, plus changes from extensions patch
	lircsettings	Allows to change lirc settings delay, freq and timeout values in OSD
	livebuffer	does timeshifting/background recording all the time, allows to rewind live TV
	lnbshare	Enables support for two or more dvb cards sharing the same cable to the lnb
	lnbsharing	Enables support for two or more dvb cards sharing the cable to the lnb
	mainmenuhooks	Allows to replace main menu entries by some special plugins (like epgsearch, extrecmenu, ...)
	menuorg	Enables support for the menuorg-plugin
	noepg	Adds code to selectively disable epg-reception for specific channels
	osdmaxitems	Support for text2skin
	parentalrating	Support Parental Rating
	pinplugin	Support for pin plugin
	rotor	Enable support for plugin vdr-rotor for dish-positioner.
	settime	set system time per script instead of via syscal
	setup	Enable support for the plugin vdr-setup
	setup-plugin	Enable support for the plugin vdr-setup
	shutdown_rewrite	use rewritten shutdown code from vdr-1.5
	softosd	Soft OSD fading with FF-Cards
	sortrecords	allows to change sort order of recordings
	sourcecaps	Adds the ability to define capabilities of dvb-cards (e.g. card1 can receive Sat @28.2E)
	submenu	Enable support for the plugin vdr-submenu.
	subtitles	Enable support for the subtitles-plugin
	switchtimer	support for timer that do not record but only switch to a channel
	syncearly	start live display as soon as possible, not waiting for sync of audio and video
	timercmd	Adds submenu for user defined commands in timer menu
	timerinfo	Show with chars +/- if space on HD will suffice for a timer
	ttxtsubs	support for ttxtsubs plugin
	validinput	Signal if it is possible to go left/right in lists with chars < >
	volctrl	allows volume control using left/right keys
	wareagleicon	Replace original icon set in menu
	yaepg	Enables support for the plugin vdr-yaepg
vlc	X	Enables support for, e.g., fullscreen mode via the X Window System. By itself, this flag does not build a graphical interface.
	atmo	Enables support for AtmoLight (homebrew Ambient Lighting Technology)
	cddax	Enables audio CD plugin with CD Text and CD paranoia via libcdio
	cdio	Enables CD input and control library support.
	dc1394	Enables IIDC cameras support.
	dirac	Enable Dirac video support (an advanced royalty-free video compression format) via the reference library: dirac.
	fluidsynth	Enables Fluidsynth MIDI software synthesis (with external sound fonts).
	gcrypt	Enables cryptography support via libgcrypt.
	gnome	Adds support for GNOME's filesystem abstraction layer, gnome-base/gnome-vfs. This flag is not GUI-related.
	httpd	Enables a web based interface for vlc.
	id3tag	Enables id3tag metadata reader plugin.
	kate	Adds support for Ogg Kate subtitles via libkate.
	libass	Enables subtitles support using libass.
	libproxy	Enables support for proxy settings in the HTTP access module.
	libsysfs	Get user key from firewire connected iPod via libsysfs.
	libtiger	Enables Ogg Kate subtitles rendering using libtiger.
	libv4l	Enables Libv4l Video4Linux support.
	libv4l2	Enables Libv4l2 Video4Linux2 support (for conversion from various video formats to standard ones, needed to use v4l2 devices with strange formats).
	live	Enables live555 streaming media support (client support for rtsp).
	optimisememory	Enable optimisation for memory rather than performance.
	pda	Builds a GTK+ interface suitable for PDA devices.
	projectm	Enables the projectM visualization plugin.
	pvr	Enables PVR cards access module.
	qt4	Builds a x11-libs/qt based frontend. It is now the most up-to-date graphical interface available.
	remoteosd	Enables RemoteOSD plugin (VNC client as video filter).
	rtsp	Enables real audio and RTSP modules.
	run-as-root	Allows vlc to start for root. Don't enable this unless you have a very specific (e.g. embedded) need for it!
	schroedinger	Enable Dirac video support (an advanced royalty-free video compression format) via libschroedinger (high-speed implementation in C of the Dirac codec).
	sdl-image	Enables sdl image video decoder (depends on sdl)
	shine	Enables shine fixed point mp3 encoder.
	shout	Enables libshout output.
	skins	Enables support for the skins2 interface.
	stream	Enables vlc to stream video.
	twolame	Enables twolame support (MPEG Audio Layer 2 encoder).
	udev	Enables Linux udev services discovery.
	upnp	Enables support for Intel UPnP stack.
	vcdinfo	Enables VCD information library support.
	vcdx	Enables VCD with navigation via libvcdinfo (depends on cdio)
	vlm	New videolan (media) manager (vlm), a little manager designed to launch and manage multiple streams from within one instance of VLC.
	wma-fixed	Enables fixed point WMA decoder.
	zvbi	Enables support for teletext subtitles via the zvbi library.
winki	mjpeg	Enables mjpegtools support
xine-ui	vdr	Enables Video Disk Recorder support

net-analyzer

Package	Flag	Description
aimsniff	http	Install the WAS (Web AIM Sniff) frontend
barnyard	sguil	Enable sguil (The Analyst Console for Network Security Monitoring) support
base	signatures	Install community signatures from net-analyzer/snort
bmon	rrdtool	Enables net-analyzer/rrdtool support
bwm-ng	csv	Enable csv output
bwm-ng	html	Enable html output
cacti	bundled-adodb	use adodb bundled with web-application instead of system wide
cacti	doc	install html documentation
echoping	http	enable support for http protocol.
	icp	enable support for ICP (used to monitor proxies).
	priority	enable socket priority support.
	smtp	enable support for SMTP protocol.
	tos	enable support for TOS (TYpe Of Service).
fprobe	messages	enable console messages
lilac	nmap	Installs nmap which can be used to automatically discover devices to monitor.
munin	irc	installs deps for monitoring IRC
	munin-apache	installs deps for monitoring apache
	munin-dhcp	installs deps for monitoring DHCP
	munin-irc	installs deps for monitoring IRC
	munin-squid	installs deps for monitoring squid
	munin-surfboard	installs deps for monitoring a Motoro Surfboard Cable modem
nagios-core	lighttpd	install www-servers/lighttpd config
nagios-core	web	enable web interface
nagios-nrpe	command-args	allow clients to specify command arguments
nagios-plugins	nagios-dns	installs deps for dns monitoring
	nagios-game	installs deps for monitoring games-util/qstat
	nagios-ntp	installs deps for ntp monitoring
	nagios-ping	installs deps for fancy ping monitoring
	nagios-ssh	installs deps for monitoring ssh
	ups	installs deps for monitoring Network-UPS (sys-power/nut)
nagvis	automap	Enable automated map generation using media-gfx/graphviz
net-snmp	diskio	Enable the use of diskio mibs
	elf	Enable the use of elf utils to check uptime on some sytems
	extensible	build deprecated extensible mib module (extend is successor)
	mfd-rewrites	Use MFD rewrites of mib modules where available
	rpm	Enable the rpm snmp probing
	sendmail	Enable sendmail statistics monitoring
	smux	Enable the smux MIBS module
pchar	pcap	Use the net-libs/libpcap library
pmacct	64bit	Use 64bit counters instead of 32bit ones
rrdtool	nls	Enable native language support (using intltool)
rrdtool	rrdcgi	Build rrdcgi support
sancp	sguil	Enable sguil (The Analyst Console for Network Security Monitoring) support
scanlogd	nids	Use net-libs/libnids for packet capturing
scanlogd	pcap	Use net-libs/libpcap for packet capturing
scapy	pyx	Enable dev-python/pyx support for psdump/pdfdump commands
	tcpreplay	Enable net-analyzer/tcpreply support for fast packet replay
	visual	Enable dev-python/visual support for 3d graphs
smokeping	speedy	Use dev-perl/SpeedyCGI instead of perl to speed up cgi scripts
snort	aruba	Enable Aruba support
	dynamicplugin	Enable ability to dynamically load preprocessors, detection engine, and rules library
	flexresp	Enable new connection tearing (not recommended)
	flexresp2	Enable new connection tearing
	gre	Enable GRE support
	inline	Enable snort-inline for accepting packets from net-firewall/iptables, via libipq, rather than net-libs/libpcap.
	inline-init-failopen	Enable inline-init-failopen support
	linux-smp-stats	Enable statistics reporting through proc on smp systems
	memory-cleanup	Enable memory-cleanup support
	mpls	Enable support for mpls networks
	perfprofiling	Enable preprocessor and rule performance profiling
	ppm	Enable ppm support
	react	Enable interception and termination of offending HTTP accesses
	reload	Enable reloading a configuration without restarting
	reload-error-restart	Enable restarting on reload error
	targetbased	Enable targetbased support
	timestats	Enable TimeStats functionality
symon	perl	Enables a generic perl symux client
	symon	Enables the lightweight system monitor. Offers no functionality but monitoring and forwarding of measured data
	symux	Enables the multiplexer which stores incoming symon streams on disk in RRD (net-analyzer/rrdtool) files
tcpdump	chroot	Enable chrooting when dropping privileges
tcpdump	smi	Build with net-libs/libsmi to load MIBs on the fly to decode SNMP packets
tcpreplay	pcapnav	Enable if you want the jump to byte offset feature via net-libs/libpcapnav
tcpreplay	tcpdump	Use net-analyzer/tcpdump for packet decoding feature
wireshark	ares	Use GNU net-dns/c-ares library to resolve DNS names
	gcrypt	Use GNU crypto library (dev-libs/libgcrypt) to decrypt SSL traffic
	pcap	Use net-libs/libpcap for network packet capturing (build dumpcap, rawshark)
	smi	Use net-libs/libsmi to resolve numeric OIDs into human readable format
zabbix	agent	Enable zabbix agent (for to-be-monitored machines)
	frontend	Enable zabbix web frontend
	openipmi	Enable openipmi things
	proxy	Enable proxy support
	server	Enable zabbix server

net-dialup

Package	Flag	Description
capi4k-utils	fax	Install capi-fax demo programs
capi4k-utils	pppd	Installs pppdcapiplugin modules
freeradius	edirectory	Enables Novell eDirectory integration
	frascend	Enables Ascend binary mode
	frxp	Enables experimental modules
	udpfromto	Compile in UDPFROMTO support (enables freeradius to specify source address correctly in multi-homed setups)
freeradius-client	scp	Add service type hints derived from username prefix
freeradius-client	shadow	Enable shadow password support
mgetty	fax	Enables fax support
mgetty	fidonet	Enables FidoNet support
misdn	ecaggressive	Make the selected echo canceller a little more aggressive
	eckb1	Use the KB1 echo canceller
	ecmark2	Use the MARK2 echo canceller
	ecmg2	Use the MG2 echo canceller (default)
ppp	activefilter	Enables active filter support
	atm	Enables ATM (Asynchronous Transfer Mode) protocol support
	dhcp	Installs PPP DHCP client plugin for IP address allocation by a DHCP server (see http://www.netservers.co.uk/gpl/)
	eap-tls	Enables support for Extensible Authentication Protocol and Transport Level Security (see http://eaptls.spe.net/index.html)
	gtk	Installs GTK+ password prompting program that can be used by passprompt.so PPP plugin for reading the password from a X11 input terminal
	ipv6	Enables support for IP version 6
	mppe-mppc	Enables support for MPPC (Microsoft Point-to-Point Compression) - NEEDS A PATCHED KERNEL <=2.6.14 (see http://mppe-mppc.alphacron.de)
	pam	Enables PAM (Pluggable Authentication Modules) support
	radius	Enables RADIUS support
pptpd	gre-extreme-debug	Log all GRE accepted packages when in debug mode (required if you want upstream support)

net-dns

Package	Flag	Description
avahi	autoipd	Build and install the IPv4LL (RFC3927) network address configuration daemon
	bookmarks	Install the avahi-bookmarks application (requires dev-python/twisted)
	howl-compat	Enable compat libraries for howl
	mdnsresponder-compat	Enable compat libraries for mDNSResponder
bind	dlz	Enables dynamic loaded zones, 3rd party extension
	resolvconf	Enable support for net-dns/openresolv
	sdb-ldap	Enables ldap-sdb backend
	urandom	Use /dev/urandom instead of /dev/random
djbdns	aliaschain	Enables a fix for the truncation of alias chains
	cnamefix	Changes the CNAME behavior of dnscache
	datadir	Enables tinydns-data to read a directory with multiple data files
	fwdonly	Enable JDP's dnscache-strict-forwardonly patch
	fwdzone	Enables the forward zone patch
	multidata	Enables command line parameters for tinydns-data to specify the data file(s)
	multipleip	Enables multi-IP patch
	roundrobin	Enables round robin patch
	semanticfix	Makes tinydns=data handle more semantic errors
dnsmasq	dhcp	Enable support for reading ISC DHCPd lease files
dnsmasq	tftp	Enables built in TFTP server for netbooting
maradns	authonly	Allows one to build only authoritative DNS server
pdns	opendbx	Enable the OpenDBX backend
pdnsd	isdn	Enable ISDN features
	underscores	Enable support for domain names containing underscores
	urandom	Use /dev/urandom instead of /dev/random

net-firewall

Package	Flag	Description
arno-iptables-firewall	plugins	Install optional plugins
ipsec-tools	hybrid	Makes available both mode-cfg and xauth support
	idea	Enable support for the patented IDEA algorithm
	nat	Enable NAT-Traversal
	rc5	Enable support for the patented RC5 algorithm
iptables	extensions	Enable support for 3rd party patch-o-matic extensions
	imq	Enable support for intermediate queueing devices (http://www.linuximq.net)
	l7filter	Enable support for layer 7 filtering (http://l7-filter.sourceforge.net)
nufw	nfconntrack	Use netfilter_conntrack
	nfqueue	Use NFQUEUE instead of QUEUE
	pam_nuauth	Add support for pam nufw from PAM
	plaintext	Add support for authentication with plaintext files

net-fs

Package	Flag	Description
netatalk	xfs	Enable support for XFS Quota
nfs-utils	nfsv3	Enable support for NFSv3
	nfsv4	Enable support for NFSv4
	nonfsv4	Disable support for NFSv4
samba	ads	Enable Active Directory support
	async	Enables asynchronous input/output
	automount	Enables automount support
	cifsupcall	Enables userspace upcall helper
	client	Enables the client part
	oav	Enables support for the OpenAntiVirus plugins
	quotas	Enables support for user quotas
	server	Enables the server part
	swat	Enables support for swat configuration gui
	winbind	Enables support for the winbind auth daemon
samba-client	ads	Enable Active Directory support
	aio	Enable asynchronous IO support
	cluster	Enable support for clustering
	samba4	Enable experimental samba4 bits
	winbind	Enables support for the winbind auth daemon
samba-libs	addns	Enable AD DNS integration
	ads	Enable Active Directory support
	aio	Enable asynchronous IO support
	cluster	Enable support for clustering
	ldb	Enable the ldb tools
	netapi	Enable building of netapi bits
	samba4	Enable experimental samba4 bits
	smbclient	Enable smbclient tool
	smbsharemodes	Enable special smb share modes (?)
	tools	Enable extra tools
	winbind	Enables support for the winbind auth daemon
samba-server	ads	Enable Active Directory support
	aio	Enable asynchronous IO support
	cluster	Enable support for clustering
	quota	Enables support for user quotas
	samba4	Enable experimental samba4 features"
	swat	Enables support for swat configuration gui
	winbind	Enables support for the winbind auth daemon

net-ftp

Package	Flag	Description
ftpcube	sftp	Enable sftp connection support
proftpd	authfile	Enable support for the auth-file module
	ban	Enable support for the mod_ban module
	case	Enable support for the mod_case module
	ctrls	Enable support for the mod_ctrls and mod_ctrls_admin modules
	deflate	Enable support for the mod_deflate module
	exec	Enable support for the mod_exec module. WARNING: this could be a security risk
	ident	Enable support for the mod_ident module
	ifsession	Enable support for the ifsession module
	noauthunix	Disable support for the auth-unix module
	opensslcrypt	Enable support for OpenSSL crypto
	ratio	Enable support for the mod_ratio module
	readme	Enable support for the mod_readme module
	rewrite	Enable support for the rewrite module
	sftp	Enable support for the mod_sftp module and optionally mod_sftp_sql and mod_sftp_pam if matching USE flags are enabled
	shaper	Enable support for the mod_shaper module
	sitemisc	Enable support for the sitemisc module
	softquota	Enable support for the quotatab module
	trace	Build with trace support. Should not be enabled on production servers
	vroot	Enable support for the virtual root module
pure-ftpd	anondel	Permit anonymous to delete files
	anonperm	Permit anonymous to change file permissions
	anonren	Permit anonymous to rename files
	anonres	Permit anonymous to resume file transfers
	charconv	Enables charset conversion
	noiplog	Disables logging of IP addresses
	paranoidmsg	Display paranoid messages instead of normal ones
	vchroot	Enable support for virtual chroot (possible security risk)
twoftpd	breakrfc	Break RFC compliance to allow control symbols in filenames (required for some (e.g. cp1251) encodings, use with caution).

net-im

Package	Flag	Description
bitlbee	nss	Use NSS for SSL support in MSN and Jabber.
centerim	gadu	Enable support for the Gadu-Gadu protocol
	irc	Enable support for the IRC protocol
	lj	Enable support for the LiveJournal weblog system
	otr	Enable encrypted conversations
climm	gloox	Enable support for Jabber/XMPP using gloox
climm	otr	Enable encrypted conversations
ejabberd	mod_irc	Irc support in ejabberd
	mod_muc	Multi user chat support in ejabberd
	mod_pubsub	Pubsub support in ejabberd
	web	Web support in ejabberd
empathy	applet	Enable Empathy's applets for gnome-base/gnome-panel
empathy	webkit	Build support for Adium-style HTML-based conversation window themes using net-libs/webkit-gtk
gajim	idle	Enable idle module
	srv	SRV capabilities
	trayicon	Enable support for trayicon
	xhtml	Enable XHTML support
gnugadu	tlen	Enable Tlen.pl protocol support
gossip	debug	Enable debug path in gossip. net-libs/loudmouth needs to be compiled with USE="debug" to allow Gossip to actually build the debug code path.
	galago	Enable desktop presence with galago
	gnome-keyring	Allows Gossip to use gnome-keyring to store passwords.
	libnotify	Allows Gossip to show visual notifications concerning various activities via libnotify.
jabberd2	memdebug	Enable nad and pool debug. Requires USE="debug" to be set.
kadu	phonon	Enable phonon audio plugin
kadu	speech	Enables speech module
kmess	konqueror	Enable integration with konqueror
mcabber	otr	Enable encrypted conversations using Off-The-Records messaging
naim	screen	Enable screen support
pidgin	bonjour	Enable bonjour support
	gadu	Enable Gadu Gadu protocol support.
	groupwise	Enable Novell Groupwise protocol support.
	meanwhile	Enable meanwhile support for Sametime protocol.
	prediction	Enable Contact Availability Prediction plugin.
	qq	Enable QQ protocol support.
	silc	Enable SILC protocol support
	zephyr	Enable Zephyr protocol support
psi	audacious	Enable monitoring of audio tracks that are played in (media-sound/audacious)
	extras	Enables extra non official patches
	insecure-patches	Enables extra non official patches that may pose as a security risk
psimedia	demo	build simple test application for the PsiMedia system.
pyaim-t	webinterface	Install dependencies needed for the web interface
pyicq-t	webinterface	Install dependencies needed for the web interface
qtwitter	oauth	Enables authorization using OAuth for Twitter accounts
sim	gpg	Enable gpg plugin to adds GnuPG encryption/decryption support for messages
	livejournal	Enable livejournal plugin to post in LiveJournal
	sms	Enable sms plugin
	weather	Enable weather plugin to get weather data from weather.com and dispaly it
skype	qt-static	Installs binaries statically linked to Qt
tkabber	extras	Enables extra non official patches
tkabber	plugins	Enables installation the extra plugins

net-irc

Package	Flag	Description
atheme	largenet	Enable support/tweaks for large networks
bip	oidentd	Enable oidentd support
ezbounce	boost	Compile against dev-libs/boost libraries
inspircd	openssl	Build dev-libs/openssl module
ircd-hybrid	contrib	Build contrib modules (eg. cloaking)
kvirc	dcc_voice	Support voice over DCC chats
	ipc	add support for IPC between kvirc processes
	phonon	use phonon instead of command-based sound
	qt-dbus	enable use of Qt's DBUS interface for IPC
	qt-webkit	enable use of Qt's WebKit
	transparency	compile in fake-transparency
ngircd	ident	Enables support for net-libs/libident
psybnc	multinetwork	Adds support for multiple networks
	oidentd	Adds support for oidentd
	scripting	Adds scripting support
quassel	X	Build the Qt 4 GUI client for quassel. If this USE flag is disabled, the GUI is not built, and cannot be used. You might want to disable this on the server, but you need it enabled on the client.
	ayatana	Build in support for Ayatana notification using the libindicate-qt plugin.
	monolithic	Build Standalone client with integrated core, no external quasselcore needed. Only useful if one don't want to use quassels client/server model. The server and X flags are not needed in this case but it is possible to enable them too.
	oxygen	Install oxygen icons. Highly recommended for KDE-4.1 and KDE-4.2 (or usage without kde). KDE-4.3 will ship the icons by default.
	phonon	Build client with phonon backend support. This enables sound playback in client.
	server	Build the server binary. If this USE flag is disabled, the 'core' server binary for quassel is not built, and cannot be used. You need this enabled on the server, but you might want to disable it on the client.
	webkit	Use qt-webkit rendering engine for showing url thumbmails and for other things that needs webbrowser intergration.
rbot	aspell	Use aspell instead of ispell in the "spell" plugin for rbot. The vanilla plugin uses ispell, but enabling this flag makes it use the ispell interface from aspell instead.
	cal	Add dependency over a package providing the /usr/bin/cal command, which is needed to enable the "cal" plugin for rbot. If the USE flag is disabled the plugin is also disabled by default.
	dict	Add dependency over dev-ruby/ruby-dict, which is needed to enable the "dict" plugin for rbot. If the USE flag is disabled the plugin is also disabled by default.
	figlet	Add dependency over app-misc/figlet, which is used by the "figlet" plugin for rbot. If the USE flag is disabled the plugin will be unable to use figlet; if toilet is also disabled, the plugin will be disabled.
	fortune	Add dependency over games-misc/fortune-mod, which is needed to enable the "fortune" plugin for rbot. If the USE flag is disabled the plugin is also disabled by default.
	host	Add dependency over net-dns/bind-tools (providing /usr/bin/host), which is needed to enable the "host" plugin for rbot. If the USE flag is disabled the plugin is also disabled by default.
	hunspell	Use hunspell instead of ispell in the "spell" plugin for rbot. The vanilla plugin uses ispell, but enabling this flag makes it use the ispell interface from hunspell instead. It's overridden by the aspell USE flag. For native hunspell support check the rbot-hunspell plugin.
	nls	Build and install translation for the messages coming from the bot and its plugins (through dev-ruby/ruby-gettext).
	shorturl	Add dependency over dev-ruby/shorturl, which is needed to enable the "shortenurl" plugin for rbot. If the USE flag is disabled the plugin is also disabled by default.
	timezone	Add dependency over dev-ruby/tzinfo to enable the "time" plugin for rbot. If the USE flag is disabled the plugin is also disabled by default.
	toilet	Add dependency over app-misc/toilet, which is used by the "figlet" plugin for rbot. If the USE flag is disabled the plugin will be unable to use toilet; if figlet is also disabled, the plugin will be disabled.
	translator	Add dependency over dev-ruby/mechanize, which is needed to enable the "translator" plugin for rbot. If the USE flag is disabled the plugin is also disabled by default.
srvx	bahamut	Choose bahamut protocol over p10 protocol
supybot	twisted	Allows supybot to use dev-python/twisted as driver
unrealircd	hub	Enable hub support
	operoverride	Enable OperOverride extension
	operoverride-verify	Enable requiring opers to invite themselves to +s/+p channels
	prefixaq	Enable chanadmin and chanowner prefixes
	showlistmodes	Support displaying channel modes in /list
	shunnotices	Enable notifying a user when un-shunned
	spoof	Enable the spoof protection
	topicisnuhost	Enable displaying nick!user@host as topic setter
	usermod	Enable /set* and /chg* commands
xchat	xchatdccserver	Enables support for the /dccserver command via a patch
xchat	xchatnogtk	Disables building the GTK front end to XChat
xchat-gnome	sound	Enable sound event support with media-libs/libcanberra
xchat-xsys	audacious	Enables media-sound/audacious integration
znc	ares	Enables support for asynchronous DNS using the c-ares library
znc	nomodules	Don't build modules

net-libs

Package	Flag	Description
aqbanking	chipcard	Enable support for DDV/RSA-chipcards
	dtaus	Enable dtaus backend
	geldkarte	Enable geldkarte backend
	hbci	Enable support for HBCI
	yellownet	Enable support for Yellownet
clinkcc	mythtv	Enable MythTV support
courier-authlib	vpopmail	Enable vpopmail support
cvm	vpopmail	Enable vpopmail support
iax	snomhack	Use slower memset for SNOM phoneem
libesmtp	ssl	Enable support for advanced SMTP authentication methods, like NTML and STARTTLS. Also use OpenSSL's MD5 implementation over internal version.
libetpan	liblockfile	Enable support for liblockfile library
libfwbuilder	bind	Use bind's name resolving library
libfwbuilder	stlport	Enagle support for STLport
libinfinity	server	Build and install the server binary including init.d/conf.d-scripts. Needed if you want to host an infinote server for gobby.
libnemesi	sctp	Support for Stream Control Transmission Protocol
libnice	upnp	Enable UPnP IGD support
libpcap	libnl	link with dev-libs/libnl (used to put wireless interfaces in monitore mode)
libpri	bri	Enable ISDN BRI support (bristuff)
libproxy	gnome	Enable support for reading proxy settings from GNOME using gnome-base/gconf
	kde	Enable support for reading proxy settings from KDE
	webkit	Enable support for reading proxy settings from net-libs/webkit-gtk
	xulrunner	Enable support for reading proxy settings from net-libs/xulrunner
libsrtp	aesicm	Use AES ICM cryptographic algorithm
	console	Use /dev/console instead of stdout for error messages
	syslog	Use syslog for error messages
libssh	gcrypt	Prefer dev-libs/libgcrypt over dev-libs/openssl for encryption
	server	Build with SSH server support
	sftp	Build with SFTP support
	ssh1	Build with SSH1 support
libssh2	gcrypt	Use dev-libs/libgcrypt for crypto
libvncserver	no24bpp	disable 24bpp support
loudmouth	asyncns	Use libasyncns for asynchronous name resolution.
netembryo	sctp	Support for Stream Control Transmission Protocol
opal	audio	Enable audio support
	capi	Enable CAPI support
	celt	Enable CELT ultra-low delay audio codec
	dtmf	Enable DTMF encoding/decoding support
	fax	Enable T.38 FAX protocol
	h224	Enable H.224 real time control protocol
	h281	Enable H.281 Far-End Camera Control protocol
	h323	Enable H.323 protocol
	iax	Enable Inter-Asterisk eXchange protocol
	ivr	Enable Interactive Voice Response
	ixj	Enable xJack cards support
	lid	Enable Line Interface Device
	noaudio	Disable audio codecs
	novideo	Disable video codecs
	plugins	Enable plugins support
	sbc	Enable the Bluetooth low-complexity, SubBand Codec
	sip	Enable Session Initiation Protocol
	sipim	Enable SIP Instant Messages session
	srtp	Enable Secure Real-time Transport Protocol
	stats	Enable statistic reporting
	swig	Use swig to generate bindings
	video	Enable video support
	vpb	Enable Voicetronics VPB card support
	vxml	Enable VXML support
	wav	Enable WAVFILE support
	x264-static	Install x264 plugin statically linked with x264
openh323	noaudio	Disable audio codecs
openh323	novideo	Disable video codecs
ortp	srtp	Add support for Secure RTP
ptlib	asn	Enable ASN decoding/encoding support
	audio	Enable audio support
	dtmf	Enable DTMF encoding/decoding support
	http	Enable HTTP support
	mail	Enable mail protocols (POP3/SMTP)
	qos	Enable QOS support
	remote	Enable remote connection support
	serial	Enable serial port support
	shmvideo	Enable shared memory video devices
	socks	Enable SOCKS protocol support
	stun	Enable STUN support
	telnet	Enable telnet protocol support
	tts	Enable Text-To-Speech server support
	video	Enable video support
	vxml	Enable VoiceXML support
	wav	Enable WAVFILE support
webkit-gtk	coverage	enable code coverage support
	pango	Use pango as fontbackend instead of freetype
	soup	Use SOUP as backend instead of curl
	websockets	enable full duplex single socket communication
	xslt	enable support for XSLT
xulrunner	custom-optimization	Fine-tune custom compiler optimizations

net-mail

Package	Flag	Description
courier-imap	trashquota	include deleted messages, and the Trash folder, in the estimated quota usage for maildirs
cyrus-imapd	idled	Enable idled vs poll IMAP IDLE method
	replication	Enable replication support in the cyrus imap server
	sieve	Enable sieve support
dbmail	sieve	Enable sieve filter support
dovecot	cydir	Adds cydir storage support
	dbox	Adds dbox storage support
	managesieve	Adds managesieve protocol support
	pop3d	Build pop3d support
	sieve	Build the sieve plugin
	vpopmail	Add vpopmail support
fetchmail	hesiod	Enable support for hesiod
gnubiff	password	Enable save passwords to connect mail servers in user space
hotwayd	smtp	Build SMTP proxy (hotsmtpd)
lbdb	abook	Enables app-misc/abook support
lbdb	finger	Enables finger support
libpst	dii	enable dii support
qmailadmin	maildrop	Filter spam using maildrop
qpopper	apop	Enables the pop.auth file in /etc/pop.auth
	drac	Enables DRAC support
	mailbox	Enables mail spool file is in home directory ~/Mailbox
teapop	virtual	Enable teapop's virtual domain support.
tpop3d	authexternal	Enable authentication by an external program
	drac	Enable dynamic relay support in the tpop3d pop3 server
	flatfile	Enable authentication against /etc/passwd-style flat files
	passwd	Enable /etc/passwd authentication
	sha1	Use OpenSSL for sha1 encrypted passwords.
	shadow	Enable /etc/shadow authentication
uw-imap	clearpasswd	Enables cleartext logins outside of SSL sessions
vchkuser	debug	Enables debug messages to syslog
vimap	clearpasswd	Enables cleartext logins outside of SSL sessions
vpopmail	clearpasswd	Enables cleartext password storage in the vpasswd files
	ipalias	Enables enable-ip-alias-domains
	maildrop	Enables mail-filter/maildrop support in vdelivermail

net-misc

Package	Flag	Description
aria2	ares	Enables support for asynchronous DNS using the c-ares library
	bittorrent	Enables support for the bittorrent protocol
	metalink	Enables support for metalink
asterisk	dahdi	Support Digium compatible hardware (formerly known as Zaptel).
	h323	Build the H.323 channel driver bundled with Asterisk
	keepsrc	Install sources into /usr/src for custom patching
	lowmem	Build Asterisk for environments with low amounts of memory (embedded devices)
	misdn	Build with mISDN (chan_misdn) support for BRI ISDN cards
	newt	Include additional tools that require redhats windowing toolkit
	nosamples	Don't install sample sound and configuration files
	osp	Enable support for the Open Settlement Protocol
	pri	Enables pri support
	span	Enable support for the spandsp codec
	zaptel	Enables deprecated zaptel support (use dahdi if available)
asterisk-addons	h323	Build the chan_ooh323c H.323 channel driver
connman	3G	Enable plugins for 3G modems net-misc/dhcp for getting ip.
	dhclient	Use dhclient from net-misc/dhcp for getting ip.
	dnsproxy	Enable dnsproxy support.
	ethernet	Enable ethernet support.
	modemmanager	Use modemmanager support from net-misc/modemmanager package.
	ofono	Use net-misc/ofono for telephony support.
	ppp	Enable ppp support.
	resolvconf	Use net-dns/openresolv for managing DNS information
	tools	Enable testing tools.
	udev	Enable udev support.
curl	ares	Enabled c-ares dns support
	gnutls	Use gnutls as the crypto engine
	libssh2	Enabled SSH urls in curl using libssh2
	nss	Use NSS as the crypto engine
	openssl	Use openssl as the crypto engine
dhcpcd	compat	Enable commandline compability with dhcpcd-3.x
directvnc	mouse	Adds mouse support
dropbear	bsdpty	Add support for legacy BSD pty's rather than dynamic UNIX pty's -- do not use this flag unless you are absolutely sure you actually want it
dropbear	multicall	Build all the programs as one little binary (to save space)
gateway6	radvd	Enable support for net-misc/radvd
gwget	epiphany	Build epiphany extensions
htbinit	esfq	Add support for Enhanced Stochastic Fairness queueing discipline.
hylafax	faxonly	Don't depend on mgetty-fax
	html	Adds HTML documentation
	mgetty	Adds support for mgetty and vgetty
iaxmodem	logrotate	Install support files for app-admin/logrotate
icecast	yp	Build support for yp public directory listings
iputils	SECURITY_HAZARD	Allow non-root users to flood (ping -f). This is generally a very bad idea.
italc	system-libvncserver	Build against the system libvncserver (experimental)
kvpnc	cisco	Adds support for Cisco client
mediatomb	libextractor	Use libextractor to gather files' metadata.
	mysql	Use dev-db/mysql as backend rather than SQLite3. If this USE flag is disabled, dev-db/sqlite is used in its stead.
	taglib	Use media-libs/taglib for reading files' metadata rather than id3lib. If this USE flag is disabled media-libs/id3lib is used in its stead.
memcached	slabs-reassign	Allow manual reassignment of memory slabs at the cost of slab optimizations.
neon	libproxy	Add support for net-libs/libproxy
neon	pkcs11	Add support PKCS11 support
networkmanager	connection-sharing	Use net-dns/dnsmasq and net-firewall/iptables for connection sharing
	dhclient	Use dhclient from net-misc/dhcp for getting ip.
	dhcpcd	Use net-misc/dhcpcd for getting ip.
	nss	Use dev-libs/nss for cryptography.
	resolvconf	Use net-dns/openresolv for managing DNS information
ntp	openntpd	Allow ntp to be installed alongside openntpd
ntp	parse-clocks	Add support for PARSE clocks
nxcl	nxclient	Use nxssh from net-misc/nxclient instead of standard ssh
nxserver-freenx	nxclient	Allow to install net-misc/nxclient in parallel with this package, using it to display messages in the sessions
ofono	udev	Use sys-fs/udev for modem detection.
oidentd	masquerade	Enable support for masqueraded/NAT connections
openssh	X509	Adds support for X.509 certificate authentication
	hpn	Enable high performance ssh
	ldap	Add support for storing SSH public keys in LDAP
	pkcs11	Enable PKCS#11 smartcard support
openswan	curl	Include curl support (used for fetching CRLs)
	extra-algorithms	Include additional strong algorithms (Blowfish, Twofish, Serpent and SHA2)
	ldap	Include LDAP support (used for fetching CRLs)
	ms-bad-proposal	Allow bad IP address proposal offered by an Microsoft L2TP/IPSec servers
	nocrypto-algorithms	Include algorithms that don't even encrypt (1DES)
	weak-algorithms	Include weak algorithms (DH1)
openvpn	eurephia	Apply eurephia patch
	iproute2	Enabled iproute2 support instead of net-tools
	passwordsave	Enables openvpn to save passwords
	pkcs11	Enable PKCS#11 smartcard support
plowshare	view-captcha	View captcha with aview
quagga	bgpclassless	Enable classless prefixes for BGP
	fix-connected-rt	Remove interface connected routes from kernel table on link loss so that no packets get routed to downed interface
	multipath	Enable multipath routes support for any number of routes
	ospfapi	Enable OSPFAPI support for client applications accessing the OSPF link state database
	realms	Enable realms support (see http://vcalinus.gemenii.ro/quaggarealms.html)
	tcp-zebra	Enable TCP zserv interface on port 2600 for Zebra/protocol-daemon communication. Unix domain sockets are chosen otherwise.
	tcpmd5	Enable TCP MD5 checksumming
rdesktop	pcsc-lite	Enable smartcard support with pcsc-lite driver
scponly	gftp	Enables gFTP compatibility
	logging	Enables SFTP logging compatibility
	passwd	Enables passwd compatibility
	quota	Enables quota compatibility
	rsync	Enables rsync compatibility with potential security risks
	scp	Enables scp compatibility with potential security risks
	sftp	Enables SFTP compatibility
	subversion	Enables Subversion compatibility with potential security risks
	unison	Enables Unison compatibility with potential security risks
	wildcards	Enables wildcard processing with potential security risks
	winscp	Enables WinSCP 2.0 compatibility with potential security risks
sitecopy	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.
sitecopy	webdav	Enable WebDav (Web-based Distributed Authoring and Versioning) support. This system allows users to collaborate on websites using a web based interface. See the ebuild for an FAQ page. Enables neon as well to handle webdav support.
streamtuner	shout	Enable shoutcast plug-in.
streamtuner	xiph	Enable xiph.org plug-in.
strongswan	cisco	Enable support of Cisco VPN client
strongswan	nat	Enable NAT traversal with IPsec transport mode
termpkg	uucp	Adds support for uucp style device locking
tigervnc	server	Build TigerVNC server
tigervnc	xorgmodule	Build the Xorg module
tightvnc	server	Build vncserver. Allows us to only build server on one machine if set, build only viewer otherwise.
tor	bundledlibevent	USE bundled libevent for asynchronous DNS requests (provides a tiny bit more anonymity)
vde	pcap	Enable the pcap-based plugin that allows creating a switch against a real interface.
vde	ssl	Enable the cryptcab plugin that allows creating an encrypted virtual cable.
vidalia	tor	Allow to use a local tor setup
vinagre	applet	Enable vinagre applet for gnome-base/gnome-panel.
	ssh	Enable ssh plugin.
	telepathy	Enable access to remote desktop via a telepathy client.
vino	telepathy	Enable desktop sharing through a telepathy client
vnc	server	Build VNC server
vnc	xorgmodule	Build the Xorg module
vpnc	hybrid-auth	Enable hybrid authentication (certificates), only if not redistributed as compiled binary
vpnc	resolvconf	Enable support for DNS managing framework net-dns/openresolv
wget	ntlm	Enable support for NTLM (Windows-based) authorization
wicd	ioctl	Installs additional python libraries to use as a backend. This will improve speed but is experimental.
	ncurses	Installs a ncurses UI
	pm-utils	Installs the pm-utils hooks for suspend/resume and requires sys-power/pm-utils
x2goserver	fuse	Use sys-fs/sshfs-fuse to allow shared folders
xsupplicant	eap-sim	Add support for EAP-SIM authentication algorithm
yaydl	soundextract	Extract the soundtracks of the downloaded videos
zaptel	astribank	Install Xorcom Astribank utilities
	bri	Enable ISDN BRI support (bristuff)
	ecaggressive	Make the mark2 echo canceller a little more aggressive
	eckb1	Use the KB1 echo canceller
	ecmark	Use the MARK echo canceller
	ecmark2	Use the MARK2 echo canceller (default)
	ecmark3	Use the MARK3 echo canceller
	ecmg2	Use the MG2 echo canceller
	ecsteve	Use the STEVE echo canceller
	ecsteve2	Use the STEVE2 echo canceller
	florz	Enable florz enhancement patches for ISDN BRI
	rtc	Use the realtime clock on x86 and amd64 systems instead of kernel timers
	watchdog	Enable the watchdog to monitor unresponsive and misbehaving interfaces
	zapnet	Enable SyncPPP, CiscoHDLC and Frame-Relay support
	zapras	Enable PPP support for Remote-Access-Service

net-nds

Package	Flag	Description
nsscache	nsscache	Depend on sys-auth/libnss-cache to handle flat files
nsscache	nssdb	Depend on sys-libs/libnss_db to handle dbm files.
openldap	experimental	Enable experimental backend options
	overlays	Enable contributed OpenLDAP overlays
	smbkrb5passwd	Enable overlay for syncing ldap, unix and lanman passwords
tac_plus	finger	Adds support for checking user counts via fingering the NAS

net-news

Package	Flag	Description
liferea	dbus	Enables the DBUS connector for liferea, so feeds can be managed from external programs
	gnutls	Enable https feeds using gnutls
	gtkhtml	Uses the gtkhtml rendering engine for item rendering. Depricated, and broken on amd64.
	libnotify	Enable popup notifications
	lua	Enable lua scripting
	networkmanager	Enable NetworkManager integration to automatically detect online/offline status
	webkit	Enable the webkit rendering engine for item rendering
	xulrunner	Enable the xulrunner 1.9 rendering engine for item rendering

net-nntp

Package	Flag	Description
inn	innkeywords	Enable automatic keyword generation support
inn	inntaggedhash	Use tagged hash table for history (disables large file support)
nzbget	parcheck	Enable support for checking PAR archives
slrn	uudeview	Add support for yEnc coding and more using dev-libs/uulib

net-p2p

Package	Flag	Description
amule	daemon	Enable amule daemon
	remote	Enable remote controlling of the client
	stats	Enable statistic reporting
	upnp	Enables support for Intel UPnP stack.
btg	event-callback	Enable calling a script or executable for certain events
	upnp	Enable support for UPnP
	webinterface	install webBTG
dbhub	switch_user	Enable support for switching user
deluge	webinterface	Install dependencies needed for the web interface
fms	frost	Add support for frost boards
freenet	freemail	Add Freemail support
gift	ares	pull in Ares plugin
	fasttrack	pull in FastTrack plugin
	gnutella	pull in Gnutella plugin
	openft	pull in OpenFT plugin
ktorrent	bwscheduler	Enable the bwscheduler plugin
	downloadorder	Enable plugin for user selected download order
	infowidget	Enable the infowidget plugin
	ipfilter	Enable the ipfilter plugin
	kross	Enable kross scripting support
	logviewer	Enable the logviewer plugin
	mediaplayer	Enable the mediaplayer plugin
	scanfolder	Enable the scanfolder plugin
	search	Enable the search plugin
	shutdown	Shutdown when done
	stats	Enable the statistics plugin
	upnp	Enable the uphp plugin
	webinterface	Enable the webinterface plugin
	zeroconf	Discover peers on the local network using the Zeroconf protocol
mktorrent	largefile	Enable largefile support on 32 bit systems
mktorrent	openssl	Use OpenSSL for md5 and sha1 support
mldonkey	fasttrack	enable fasttrack support
	gnutella	enable gnutella and gnutella2 support
	guionly	enable client build only
	magic	enable use of libmagic
museek+	qsa	Enable QSA scripting for museeq
museek+	trayicon	Enable support for trayicon
rtorrent	daemon	Uses app-misc/screen to daemonize this application"
transmission	dht	Enable Distributed Hash Tables support

net-print

Package	Flag	Description
hplip	cupsddk	Add support for net-print/cupsddk which enables dynamic PPD files (recommended)
	dbus	Add support for sys-apps/dbus which enables better communications with your device (recommended)
	doc	Build documentation
	fax	Enable fax on multifunction devices which support it
	gtk	Enable GTK+ dependencies, currently only the scanner GUI with USE=scanner
	hpcups	Build the hpcups driver for cups (by HP)
	hpijs	Build the IJS driver for cups (Foomatic)
	libnotify	Enables desktop notifications
	minimal	Only build internal hpijs driver (not recommended at all, make sure you know what you are doing)
	new-hpcups	Build the new hpcups driver for cups which is no longer based on APDK (by HP)
	parport	Enable parallel port for devices which require it
	policykit	Enable sys-auth/policykit authentication support
	ppds	Use precompiled PPD files (obsolete, use cupsddk instead)
	qt3	Enable graphical interface using Qt 3; when both qt3 and qt4 USE flags are enabled then qt4 has priority over qt3
	qt4	Enable graphical interface using Qt 4; when both qt3 and qt4 USE flags are enabled then qt4 has priority over qt3
	scanner	Enable scanner on multifunction devices which support it
	snmp	Add support for net-analyzer/net-snmp which enables this driver to work over networks (both for server and client)
	static-ppds	Use statically-generated PPDs instead of Dynamic PPDs. This is deprecated, and this USE flag is thus suggested to stay turned off
	udev-acl	Install udev acl rules which needs sys-fs/udev with acl support
	zeroconf	Zeroconf support. Enable this flag to make use of the mDNS network search for network attached printers
pkpgcounter	psyco	psyco python accelerator

net-proxy

Package	Flag	Description
dansguardian	kaspersky	Adds support for Kaspersky AntiVirus software
dansguardian	ntlm	Enable support for the NTLM auth plugin
squid	ecap	Adds support for loadable content adaptation modules (http://www.e-cap.org)
	epoll	Enables Linux epoll() support
	icap-client	Adds ICAP client support
	ipf-transparent	Adds transparent proxy support for systems using IP-Filter (only for *bsd)
	kqueue	Enables *BSD kqueue() support
	logrotate	Use app-admin/logrotate for rotating logs
	pf-transparent	Adds transparent proxy support for systems using PF (only for *bsd)
	zero-penalty-hit	Add Zero Penalty Hit patch (http://zph.bratcheda.org)
sshproxy	client-only	Install only the client wrappers
tinyproxy	transparent-proxy	Enables support for transparent proxies
tsocks	tordns	Apply tordns patch which allows transparent TORification of the DNS queries

net-voip

Package	Flag	Description
ekiga	gconf	Enable GConf support
	h323	Enable H.323 protocol
	shm	Enable the Shared Memory Extension from libXext
	static	Statically link to opal and ptlib
	xcap	Enable XML Configuration Access Protocal
linphone	video	Enable video support (display/capture)
telepathy-connection-managers	bonjour	Enable Link-Local Messaging via the bonjour protocol.
	irc	Enable Internet Relay Chat (IRC) support.
	jabber	Enable XMPP protocol handler (this is also Google Talk).
	sip	Enable SIP/SIMPLE messaging and calling.
	yahoo	Enable Yahoo! messaging support.
twinkle	ilbc	Enables use of ilbc (RFC3951) audio encoding
twinkle	zrtp	Enables use of secure rtp using the zrtp extension of GNU RTP stack developed by Phil Zimmermann
yate	amrnb	Enables Adaptive Multi-Rate Audio support (Narrow Band)
	h323	Build H.323 Channel plugin
	ilbc	Build ILBC codec plugin
	sctp	Support for Stream Control Transmission Protocol
	spandsp	Enable support for the spandsp codec
	zaptel	Build zaptel Channel plugin

net-wireless

Package	Flag	Description
blueman	network	Add functionality to setup (host) PAN connections using either net-dns/dnsmasq or net-misc/dhcp
bluez	consolekit	Use sys-auth/pambase[consolekit] to determine access to bluetooth devices based on whether a user is logged in locally or remotely
	old-daemons	Install old daemons like hidd and sdpd that are deprecated by the new Service framework
	test-programs	Install l2test and rctest
bluez-utils	old-daemons	Install old daemons like hidd and sdpd that are deprecated by the new Service framework
bluez-utils	test-programs	Install l2test and rctest
hostapd	logwatch	Install support files for sys-app/logwatch
	madwifi	Add support for madwifi (Atheros chipset)
	wps	Add support for Wi-Fi Protected Setup
madwifi-ng	injection	Adds support for net-wireless/aircrack-ng aireplay-ng packet injection
madwifi-old	amrr	Use Adaptive Multi Rate Retry bit rate control algorithm
madwifi-old	onoe	Use Atsushi Onoe's bit rate control algorithm
wepattack	john	Build with app-crypt/johntheripper support
wifiscanner	wireshark	Use the net-analyzer/wireshark wtap library
wireless-tools	multicall	Build the most commonly used tools as one binary
wpa_supplicant	eap-sim	Add support for EAP-SIM authentication algorithm
	madwifi	Add support for madwifi (Atheros chipset)
	ps3	Add support for ps3 hypervisor driven gelic wifi
	wps	Add support for Wi-Fi Protected Setup

rox-base

Package	Flag	Description
rox	video	Enable rox-extra/videothumbnail for creating thumbnails of videos with mplayer or totem.

rox-extra

Package	Flag	Description
archive	ace	Enable .ace extraction via app-arch/unace
	compress	Enable tar.Z and *.Z extraction via app-arch/ncompress
	cpio	Enable .cpio extraction via app-arch/cpio
	rar	Enable .rar extraction via app-arch/unrar
	rpm	Enable .rpm extraction via rpm2cpio from app-arch/rpm
	uuencode	Enable .uue extraction via app-arch/sharutils
	zip	Enable .zip extraction via app-arch/unzip and app-arch/zip
comicthumb	rar	Enable support for rar-compressed archives via app-arch/unrar
magickthumbnail	xcf	Enable previews of .xcf files using media-gfx/gimp

sci-astronomy

Package	Flag	Description
orsa	cln	Use the Class Library for Numbers (sci-libs/cln) for calculations
predict	xforms	Add a "map" client which uses the x11-libs/xforms library for its GUI
predict	xplanet	Project predict data onto world maps generated by x11-misc/xplanet / x11-misc/xearth
scamp	plplot	Build with sci-libs/plplot to allow diagnostic plots during processing

sci-biology

Package	Flag	Description
bioperl	db	Install sci-biology/bioperl-run
	network	Install sci-biology/bioperl-run
	run	Install sci-biology/bioperl-run
clustalw-mpi	mpi_njtree	Use MPI (as opposed to serial) code for computing neighbor-joining trees
clustalw-mpi	static_pairalign	Use static (as opposed to dynamic) scheduling for pair alignments
exonerate	largefile	Enable largefile support on 32 bit systems
exonerate	utils	Install all utilities
hmmer	pvm	Add support for parallel virtual machine (sys-cluster/pvm)
mcl	blast	add support for NCBI BLAST data
plink	webcheck	add support for online update checking every time the program starts
ucsc-genome-browser	server	Install genome browser Web application. If this flag is off, only libraries and utilities from the suite are installed.

sci-chemistry

Package	Flag	Description
apbs	arpack	Include support for arpack libs
avogadro	glsl	Enable glsl features via GLEW.
caver	pymol	Install the PyMol plugin (sci-chemistry/pymol)
coot	new-interface	Build with the experimental GTK+-2 interface instead of GTK+-1
eden	double-precision	More precise calculations at the expense of speed
gamess	qmmm-tinker	Enable tinker qmmm code
ghemical	gamess	Add GAMESS interface for QM/MM (sci-chemistry/gamess)
	mopac7	Apply compilation fix for sci-chemistry/mopac7 support
	openbabel	Use sci-chemistry/openbabel for file conversions
	toolbar	Build the shortcuts toolbar
gromacs	dmalloc	Enable use of Debug Malloc
	double-precision	More precise calculations at the expense of speed
	fkernels	Enable building of Fortran Kernels for platforms that dont have assembly loops
	single-precision	Single precision version of gromacs
jmol	client-only	Install the viewer only, no applet files for httpd
openbabel	swig	Use swig to rebuild language bindings.
pdb2pqr	opal	Add web interafce via opal
pymol	apbs	Build the apbs plugin tool.
pymol	shaders	Build with Shaders support - good for high-end 3D video cards.
shelx	dosformat	Use CR/LF to end lines; useful in mixed Linux/Windows environments
wxmacmolplt	flash	Add support for flash movie generation using media-libs/ming

sci-electronics

Package	Flag	Description
geda	stroke	enable mouse gesture support
geda-gschem	stroke	enable mouse gesture support
gerbv	unit-mm	Set default unit for coordinates in status bar to mm
kicad	dev-doc	Install developer documentation (requires app-doc/doxygen)
pcb	gif	GIF graphics export
	jpeg	JPEG graphics export
	nelma	NELMA file export
	png	PNG graphics export
	threads	Enable (posix) threads for GTK GUI
	tk	Build tcl/tk graphical QFP footprint generator
	xrender	Translucent PCB display for Motif/Lesstif GUI

sci-geosciences

Package	Flag	Description
gmt	gmtfull	Full resolution bathymetry database
	gmthigh	Add high resolution bathymetry database
	gmtsuppl	Supplement functions for GMT
	gmttria	Non GNU triangulation method, more efficient
gpsd	garmin	Enable support for Garmin simple text protocol
	minimal	Reduced install set, limited number of devices and client, no X deps
	ntp	Enable net-misc/ntp shared memory interface and PPS kernel support for GPS time
	ocean	Enable OceanServer support
	tntc	Enable True North Technologies digital compass support
grass	gdal	Enable support for sci-libs/gdal (Grass 5 only)
	gmath	Enable gmath wrapper for BLAS/Lapack (virtual/blas, virtual/lapack)
	largefile	Enable LFS support for huge files
mapnik	gdal	Enable sci-libs/gdal library support
mapserver	agg	Enable x11-libs/agg library support
	flash	Add support for creating SWF files using media-libs/ming
	gdal	Enable sci-libs/gdal library support
	geos	Enable sci-libs/geos library support
	postgis	Enable dev-db/postgis support
	proj	Enable sci-libs/proj library support (geographic projections)
merkaartor	gdal	Enable sci-libs/gdal library support
	proj	Enable sci-libs/proj library support
	webkit	Enable net-libs/webkit-gtk library support
qgis	grass	Add support for sci-geosciences/grass

sci-libs

Package	Flag	Description
acml	gfortran	Fetch and install acml compiled with GNU gfortran
	ifc	Fetch and install acml compiled with Intel Fortran Compiler (dev-lang/ifc)
	int64	Install the 64 bits integer library
arprec	qd	Use sci-libs/qd
blas-goto	int64	Build the 64 bits integer library
cholmod	metis	Enable the Partition module to cholmod using metis (sci-libs/metis, sci-libs/parmetis)
cholmod	supernodal	Enable the Supernodal module (needs virtual/lapack)
fftw	float	Link default library to single precision instead of double (symlinks only and fftw-2.1)
gdal	ecwj2k	Enable support for alternate jpeg2k library sci-libs/libecwj2
	fits	Enable support for NASA's sci-libs/cfitsio library
	geos	Add support for geometry engine (sci-libs/geos
	gml	Enable support for dev-libs/xerces-c C++ API
	hdf	Add support for the Hierarchical Data Format v. 4 (sci-libs/hdf)
	ogdi	Enable support for the open geographic datastore interface (sci-libs/ogdi)
gerris	dx	Enable support for sci-visualization/opendx
gsl	cblas	Link gsl with external cblas provided by (virtual/cblas)
hdf5	f90	Override Fortran for externel compilers
	hlapi	Enable support for high-level library
	tools	Install support and test tools
indilib	fits	Enable support for the FITS image format through cfitsio
indilib	nova	Enable support for nova celestial mechanics calculations
libgeda	threads	Enable (posix) threads for the GTK GUI
libghemical	mopac7	Use sci-chemistry/mopac7 for semi-empirical calculations
libghemical	mpqc	Use sci-chemistry/mpqc for quantum-mechanical calculations
libnc-dap	full-test	Enables full set of regression tests (long).
libsvm	tools	Install support tools
mathgl	octave	Add bindings for sci-mathematics/octave
metis	int64	Build the 64 bits integer library (metis >=5 only)
mkl	fortran95	Installs the BLAS/LAPACK FORTRAN95 static libraries
	int64	Installs the 64 bits integer libraries
	serial	Installs the serial (as non-threaded) libraries
nlopt	octave	Add plugin for sci-mathematics/octave
plplot	ada	Add bindings for the ADA programming language
	itcl	Add bindings for dev-tcltk/itcl
	jadetex	Add device for app-text/jadetex (for processing tex files produced by the TeX backend of Jade)
	octave	Add bindings for sci-mathematics/octave
	qhull	Add bindings for media-libs/qhull bindings
scipy	umfpack	Adds support for sparse solving with sci-libs/umfpack
spqr	metis	Use METIS (sci-libs/metis or sci-libs/parmetis) for partitioning
spqr	tbb	Enable multithreading with the Intel Threads Building Block (needs dev-cpp/tbb)
suitesparse	metis	Use METIS (sci-libs/metis or sci-libs/parmetis) for partitioning
taucs	cilk	Enable multithreading using dev-lang/cilk)
taucs	metis	Add partioning support using metis (sci-libs/metis, sci-libs/parmetis)
vtk	boost	Add support for boost
	cg	Use nvidia's cg shaders
	patented	Build patented classes

sci-mathematics

Package	Flag	Description
cgal	taucs	Add support for the sparse solver library sci-libs/taucs
coq	norealanalysis	Do not build real analysis modules (faster compilation)
dataplot	gs	Add Ghostscript support (virtual/ghostscript)
freemat	arpack	Add sparse eigen value support via sci-libs/arpack
	ffcall	Enable use of dev-libs/ffcall
	umfpack	Add sparse solving via sci-libs/umfpack
geomview	avg	Enable experimental motion averaging technique
geomview	netpbm	Add media-libs/netpbm support for external modules
gretl	sourceview	Enable support for x11-libs/gtksourceview
maxima	clisp	Add support for GNU CLISP (dev-lisp/clisp)
	cmucl	Add support for CMU Common Lisp (dev-lisp/cmucl)
	ecl	Add support for Embeddable Common Lisp (dev-lisp/ecls)
	gcl	Add support for GNU Common Lisp (dev-lisp/gcl)
	sbcl	Add support for Steel Bank Common Lisp (dev-lisp/sbcl)
nusmv	minisat	Enable support for MiniSat
octave	sparse	Enable enhanced support for sparse matrix algebra
octave-forge	qhull	Add support for media-libs/qhull (geometric extensions)
pari	data	Add additional data (elldata, galdata, seadata, nftables)
	elliptic	Add additional elliptic curve data
	galois	Add additional data to compute Galois groups of degree 8 to 11
singular	boost	Compile against external boost headers (dev-libs/boost)
yacas	server	Build the network server version

sci-misc

Package	Flag	Description
boinc	client	Build client part of the boinc. Not only the manager but also the computation unit. With +X only you will have only manager which can connect to remote clients.
	cuda	Use nvidia cuda toolkit for speeding up computations. NOTE: works only for subset of nvidia graphic cards so make sure your card is supported before opening bug about it.
	server	Enable compilation of server
h5utils	octave	Build Octave plugins
nco	ncap2	Build next generation netcdf arithmetic processor (needs dev-java/antlr)
nco	udunits	Add sci-libs/udunits files support
ncview	udunits	Add sci-libs/udunits files support

sci-physics

Package	Flag	Description
cernlib-montecarlo	herwig	Build Herwig internal event generator, newer version available in sci-physics/herwig
clhep	exceptions	Enable zoom exceptions for user intervention
geant	aida	Add support for Abstract Interfaces for Data Analysis
	athena	Enable the MIT Athena (x11-libs/libXaw) widget set (default is Motif)
	data	Add a lot of standard physics data files for geant4
	dawn	Add support for media-gfx/dawn (3D postscript rendering)
	gdml	Enable geometry markup language for xml
	geant3	Add compatibility for geant321 to geant4
	global	Produce a huge global library instead of small ones
	openinventor	Add support for media-libs/openinventor SGI toolkit
	raytracerx	Enable raytracing for physics events
	vrml	Enable output of geant4 in vrml formats
hepmc	cm	Build with cm instead of default mm for length units
hepmc	gev	Build with GeV instead of default MeV for momentum units
lhapdf	data	Install all Parton Density Function data sets system-wide
pythia	hepmc	Adds support for High Energy Physics Monte Carlo Generators sci-physics/hepmc
root	cern	Build the HBOOK input/ouput functionality, needs fortran or sci-physics/cernlib
	cint7	Build the experimental new C++ interpretor CINT7
	clarens	Buld the Clarens and PEAC plug-ins, to use in a GRID enabled analysis.
	geant4	Build the sci-physics/geant (GEANT4) navigator
	math	Build all math related libraries plugins, needs sci-libs/gsl
	pythia6	Builds the interface to Pythia-6 (sci-physics/pythia) high energy physics generation events library
	pythia8	Builds the interface to Pythia-8 (sci-physics/pythia) high energy physics generation events library
	reflex	Builds the reflection database for the C++ interpretor
	xrootd	Build the xrootd low latency file server

sci-visualization

Package	Flag	Description
gnuplot	gd	Add support for media-libs/gd. Needed for GIF, JPEG, and PNG image output.
gwyddion	sourceview	Enable support for x11-libs/gtksourceview
hippodraw	fits	Enable HippoDraw's built-in support for reading FITS files, by using the CFITSIO library. FITS binary and ASCII tables are supported as well as images. When combine with numpy flag, it can also use the pyfits package.
	numpy	Enable support for the numerical array manipulation and computational capabilities of numpy in python. HippoDraw can return a numerical array to Python from any of the type of objects that are supported. One can also import data to a HippoDraw from a numpy array.
	root	Adds support for ROOT input/ouput system, storing a table of data as TBranch objects each with a single TLeaf. Files of this type can be imported by HippoDraw as a RootNTuple. Also if root flag is selected, it can use root::minuit for minimization instead of standalone minuit library.
	wcs	Adds 10 built-in transforms to HippoDraw via the World Coordinate System library for FITS files.
labplot	R	Add statistical dev-lang/R support
	cdf	Add support for sci-libs/cdf data exchange format
	kexi	Import and export data from/to MySQL, PostgreSQL etc. via Kexi (app-office/kexi)
	qhull	Add media-libs/qhull (geometric extensions) support
opendx	cdf	Add support for sci-libs/cdf data exchange format
opendx	hdf	Add support for the Hierarchical Data Format (sci-libs/hdf)
paraview	boost	Enable the usage of dev-libs/boost
paraview	plugins	Build and install additional plugins
veusz	fits	Add FITS format via dev-python/pyfits

sys-apps

Package	Flag	Description
acl	nfs	add support for NFS acls
busybox	make-symlinks	Create all the appropriate symlinks in /bin and /sbin.
gawk	libsigsegv	Support segfault recovery/debugging
gnome-disk-utility	nautilus	enable gnome-base/nautilus extension.
hal	acpi	Enables HAL to attempt to read from /proc/acpi/event, if unavailable, HAL will read events from sys-power/acpid. If you need multiple acpi readers, ensure acpid is in your default runlevel (rc-update add acpid default) along with HAL. This will also enable HAL to read Toshiba and IBM acpi events which do not get sent via /proc/acpi/event
	consolekit	Enables HAL to interact with consolekit for determining whether a given process is running on behalf of the person setting at the console.
	crypt	Allows HAL to mount volumes that are encrypted using LUKS. sys-fs/cryptsetup-luks which has recently been renamed to sys-fs/cryptsetup allows you to create such encrypted volumes. HAL will be able to handle volumes that are removable or fixed.
	dell	Builds and installs the Dell addon, which reads data from the Dell SM BIOS via sys-libs/libsmbios. It will read your service tag information and your hardware backlight data as well as allow you to modify the backlight settings on a Dell laptop.
	disk-partition	Allows HAL to use libparted from sys-apps/parted to read raw partition data from your disks and process that data. Future versions of HAL (possibly 0.5.11 and higher) will allow you to create, modify, delete and format partitions from a GUI interface agnostic of your desktop environment.
	doc	Generates documentation that describes HAL's fdi format.
	laptop	Adds support for power management scripts (sys-power/pm-utils)
	selinux	Installs SELinux policies and links HAL to the SELinux libraries.
halevt	rpath	Hardcode runtime library paths
hwdata-gentoo	binary-drivers	Adds support for ATI/NVIDIA binary drivers
ipmitool	openipmi	Use the system OpenIPMI implementation.
kexec-tools	xen	Enable extended xen support
lm_sensors	sensord	Enable sensord - a daemon that can be used to periodically log sensor readings from hardware health-monitoring chips
man	lzma	Uses app-arch/lzma-utils for the COMPRESS feature. Could also be used to guarantee that lzma is on the system.
memtest86	serial	Compile with serial console support
memtest86+	floppy	Install a script to create floppy disks containing memtest86+ binaries.
memtest86+	serial	Compile with serial console support
paludis	inquisitio	Enable inquisitio, the search client
	pink	Use a less boring colourscheme than the default
	portage	Enable experimental support for Portage configuration formats
	python-bindings	Enable Python bindings. Requires a lot of RAM to build (~700Mbytes per job) and adds a dependency upon dev-libs/boost
	qa	Enable QA tools
	ruby-bindings	Enable Ruby bindings.
	visibility	Enable visibility support (g++ >=4.1)
parted	device-mapper	Enable sys-fs/device-mapper support in parted
pciutils	network-cron	Monthly cronjob the update-pciids script
pcmcia-cs	trusted	Assume all users are trusted (Build unsafe user-space tools)
pcmcia-cs	xforms	Enable building the xforms based cardinfo binary
pcmcia-cs-modules	cardbus	Enable 32bit CardBus support
pcmciautils	staticsocket	Add support for static sockets
portage	epydoc	Build html API documentation with epydoc.
portage	python3	Use python3 as Python interpreter.
qingy	opensslcrypt	Encrypt communications between qingy and its GUI using dev-libs/openssl
qtparted	jfs	Include JFS support
	ntfs	Include NTFS support
	reiserfs	Include ReiserFS support
	xfs	Include XFS support
s390-tools	zfcpdump	build the kernel disk dumping utility
shadow	audit	Enable support for sys-process/audit
shadow	nousuid	When nousuid is enabled only su from the shadow package will be installed with the setuid bit (mainly for single user systems)
smartmontools	minimal	Do not install the monitoring daemon and associated scripts.
tuxonice-userui	fbsplash	Add support for framebuffer splash
ucspi-ssl	tls	Add TLS support (see also http://www.suspectclass.com/~sgifford/ucspi-tls/)
usbutils	network-cron	Monthly cronjob the update-usbids script
util-linux	loop-aes	include support for Loop AES encryption
util-linux	perl	install the chkdupexe helper script
v86d	x86emu	Use x86emu for Video BIOS calls

sys-auth

Package	Flag	Description
consolekit	policykit	Use the PolicyKit framework (sys-auth/policykit) to get authorization for suspend/shutdown.
pam_mysql	openssl	Use OpenSSL for md5 and sha1 support
pam_pkcs11	pcsc-lite	build with sys-apps/pcsc-lite instead of dev-libs/openct
pambase	consolekit	Enable pam_ck_connector module on local system logins. This allows for console logins to make use of ConsoleKit authorization.
	cracklib	Enable pam_cracklib module on system authentication stack. This produces warnings when changing password to something easily crackable. It requires the same USE flag to be enabled on sys-libs/pam or system login might be impossible.
	debug	Enable debug information logging on syslog(3) for all the modules supporting this in the system authentication and system login stacks.
	gnome-keyring	Enable pam_gnome_keyring module on system login stack. This enables proper Gnome Keyring access to logins, whether they are done with the login shell, a Desktop Manager or a remote login systems such as SSH.
	mktemp	Enable pam_mktemp module on system auth stack for session handling. This module creates a private temporary directory for the user, and sets TMP and TMPDIR accordingly.
	passwdqc	Enable pam_passwdqc module on system auth stack for password quality validation. This is an alternative to pam_cracklib producing warnings, rejecting or providing example passwords when changing your system password. It is used by default by OpenWall GNU/*/Linux and by FreeBSD.
	sha512	Switch Linux-PAM's pam_unix module to use sha512 for passwords hashes rather than MD5. This option requires >=sys-libs/pam-1.0.1 built against >=sys-libs/glibc-2.7, if it's built against an earlier version, it will silently be ignored, and MD5 hashes will be used. All the passwords changed after this USE flag is enabled will be saved to the shadow file hashed using SHA512 function. The password previously saved will be left untouched. Please note that while SHA512-hashed passwords will still be recognised if the USE flag is removed, the shadow file will not be compatible with systems using an earlier glibc version.
	ssh	Enable pam_ssh module on system auth stack for authentication and session handling. This module will accept as password the passphrase of a private SSH key (one of ~/.ssh/id_rsa, ~/.ssh/id_dsa or ~/.ssh/identity), and will spawn an ssh-agent instance to cache the open key.

sys-block

Package	Flag	Description
gparted	dmraid	Support for dmraid devices, also known as ATA-RAID, or Fake RAID.
	fat	Include FAT16/FAT32 support (sys-fs/dosfstools)
	hfs	Include HFS support (sys-fs/hfsutils)
	jfs	Include JFS support (sys-fs/jfsutils)
	ntfs	Include NTFS support (sys-fs/ntfsprogs)
	reiser4	Include ReiserFS4 support (sys-fs/reiser4progs)
	reiserfs	Include ReiserFS support (sys-fs/reiserfsprogs)
	xfce	Enable integration in XFCE desktop
	xfs	Include XFS support (sys-fs/xfsprogs, sys-fs/xfsdump)
open-iscsi	modules	Build the open-iscsi kernel modules
open-iscsi	utils	Build the open-iscsi utilities
partimage	nologin	Do not include login support
unieject	pmount	Make use of pmount wrapper and pmount-like permissions (sys-apps/pmount)

sys-boot

Package	Flag	Description
arcboot	cobalt	Disable support for Cobalt Microserver hardware (Qube2/RaQ2)
	ip27	Disable support for SGI Origin (IP27)
	ip28	Disable support for SGI Indigo2 Impact R10000 (IP28)
	ip30	Disable support for SGI Octane (IP30)
grub	multislot	Allow grub1 and grub2 to be installed simultaneously
lilo	device-mapper	Enable support for sys-fs/device-mapper
lilo	pxeserial	Avoid character echo on PXE serial console

sys-cluster

Package	Flag	Description
charm	cmkopt	Enable CMK optimisation
charm	tcp	Use TCP (instead of UPD) for socket communication
glusterfs	fuse	Add FUSE mount helper
heartbeat	ldirectord	Adds support for ldiretord, use enabled because it has a lot of deps
heartbeat	management	Adds support for management GUI.
lam-mpi	pbs	Add support for the Portable Batch System (PBS)
	romio	Enable romio, a high-performance portable MPI-IO implementation
	xmpi	Build support for the external XMPI debugging GUI
mpi-dotnet	doc	Install tutorials for C# and IronPython (requires a Word document reader)
mpi-dotnet	examples	Install small, illustrative projects using MPI.Net
mpich2	fast	Enabling fast turns off error checking and timing collection
	mpe	Add mpe support
	mpe-sdk	Include additional SDK support, jar files
	mpi-threads	Enable MPI_THREAD_MULTIPLE
	pvfs2	Add pvfs2 support
	romio	Enable romio, a high-performance portable MPI-IO implementation
ocfs	aio	Add aio support
openmpi	heterogeneous	Enable features required for heterogeneous platform support
	mpi-threads	Enable MPI_THREAD_MULTIPLE
	pbs	Add support for the Portable Batch System (PBS)
	romio	Build the ROMIO MPI-IO component
	vt	Enable bundled VampirTrace support
pvfs2	apidocs	Build API documentation directly from the code using doxygen
pvfs2	server	Enable compilation of server code
torque	cpusets	Enable pbs_mom to utilize linux cpusets if available.
	drmaa	Enable the Distributed Resource Management Application API.
	server	Enable compilation of pbs_server and pbs_sched.

sys-devel

Package	Flag	Description
binutils	gold	Use the new gold linker (written in C++) rather than the standard linker (this _will_ break things)
	multislot	Allow for multiple versions of binutils to be emerged at once for same CTARGET
	multitarget	Adds support to binutils for cross compiling (does not work with gas)
binutils-hppa64	gold	Use the new gold linker (written in C++) rather than the standard linker (this _will_ break things)
	multislot	Allow for multiple versions of binutils to be emerged at once for same CTARGET
	multitarget	Adds support to binutils for cross compiling (does not work with gas)
binutils-nios2	gold	Use the new gold linker (written in C++) rather than the standard linker (this _will_ break things)
	multislot	Allow for multiple versions of binutils to be emerged at once for same CTARGET
	multitarget	Adds support to binutils for cross compiling (does not work with gas)
clang	static-analyzer	Install the Clang static analyzer
gcc	d	Enable support for the D programming language
	fixed-point	Enable fixed-point arithmetic support for MIPS targets in gcc (Warning: significantly increases compile time!)
	graphite	Add support for the framework for loop optimizations based on a polyhedral intermediate representation
	ip28	Enable building a compiler capable of building a kernel for SGI Indigo2 Impact R10000 (IP28)
	ip32r10k	Enable building a compiler capable of building an experimental kernel for SGI O2 w/ R1x000 CPUs (IP32)
	libffi	Build the portable foreign function interface library
	mudflap	Add support for mudflap, a pointer use checking library
	multislot	Allow for SLOTs to include minor version (3.3.4 instead of just 3.3)
	n32	Enable n32 ABI support on mips
	n64	Enable n64 ABI support on mips
	nopie	Disable PIE support (NOT FOR GENERAL USE)
	nossp	Disable SSP support (NOT FOR GENERAL USE)
	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
gcc-apple	multislot	Allow for SLOTs to include minor version (3.3.4 instead of just 3.3)
	objc	Build support for the Objective C code language
	objc++	Build support for the Objective C++ language
gcc-nios2	multislot	Allow for SLOTs to include minor version (3.3.4 instead of just 3.3)
gdb	multitarget	Support all known targets in one gdb binary
kgcc64	multislot	Allow for SLOTs to include minor version (eg. 3.3.4 instead of just 3.3)
libperl	ithreads	Enable Perl threads, has some compatibility problems
llvm	alltargets	Build all host targets (default: host only)
	libffi	Add support to call arbitrary external (natively compiled) functions via dev-libs/libffi
	llvm-gcc	Build LLVM with sys-devel/llvm-gcc
llvm-gcc	bootstrap	Compile the final llvm-gcc executables with llvm-gcc itself
	objc	Build support for the Objective C code language
	objc++	Build support for the Objective C++ language

sys-freebsd

Package	Flag	Description
freebsd-lib	gpib	Enable General Purpose Interface Bus support
	hesiod	Enable support for net-dns/hesiod
	netware	Build libraries and tools to work with NetWare protocols (IPX and NCP).
freebsd-sbin	ipfilter	Build tools to administer the ipfilter firewall.
	netware	Build libraries and tools to work with NetWare protocols (IPX and NCP).
	pf	Build tools to administer the PF firewall.
	vinum	Enable vinum support (TODO improve description)
freebsd-share	isdn	Enable ISDN support
freebsd-ubin	audit	Build auditing tools.
freebsd-ubin	netware	Build libraries and tools to work with NetWare protocols (IPX and NCP).
freebsd-usbin	audit	Build auditing tools.
	ipfilter	Enable building of ipfilter firewall support.
	ipsec	Enable IPSec support.
	isdn	Enable ISDN support.
	nat	Enable Network Address Translation support daemon.
	netware	Build libraries and tools to work with NetWare protocols (IPX and NCP).

sys-fs

Package	Flag	Description
aufs2	debug	Enable additional debugging support
	inotify	Enable inotify support
	kernel-patch	Patch the current kernel for aufs2 support
	ramfs	Enable initramfs/rootfs support
btrfs-progs	debug-utils	Build additional utils for debugging
cryptsetup	dynamic	Build cryptsetup dynamically
ecryptfs-utils	gpg	Enable app-crypt/gnupg key module
	nss	Enable support for dev-libs/nss
	openssl	Enable dev-libs/openssl key module
	pkcs11	Enable PKCS#11 (Smartcards) key module
	tpm	Enable support for Trusted Platform Module (TPM) using app-crypt/trousers
evms	hb	Enable support for heartbeat-1
evms	hb2	Enable support for heartbeat-2
loop-aes	extra-ciphers	Enable extra ciphers
	keyscrub	Protects the encryption key in memory but takes more cpu resources
	padlock	Use VIA padlock instructions, detected at run time, code still works on non-padlock processors
lvm2	clvm	Allow users to build clustered lvm2
	cman	Cman support for clustered lvm
	lvm1	Allow users to build lvm2 with lvm1 support
	nolvmstatic	Allow users to build lvm2 dynamically
ntfs3g	external-fuse	Use external FUSE library instead of internal one. Must be disabled for unprivileged mounting to work.
ntfsprogs	fuse	Build a FUSE module
owfs	ftpd	Enable building the OWFS FTP server (owftpd)
	fuse	Enable building the FUSE-based OWFS client (owfs)
	httpd	Enable building the OWFS web server (owhttpd)
	parport	Enable support for the DS1410E parallel port adapter
	server	Enable building the OWFS server (owserver)
quota	rpc	Enable quota interaction via RPC
udev	devfs-compat	Install rules for devfs compatible device names
udev	extras	Compile udev-extras requiring external dependencies
unionfs	nfs	Adds support for NFS file system

sys-kernel

Package	Flag	Description
dracut	dmraid	Add support for dmraid devices, also known as ATA-RAID, or Fake RAID.
	iscsi	Add support for iSCSI
	lvm	Add support for the Logical Volume Manager sys-apps/lvm2
	md	Add support for MD devices, also known as software raid devices
	nbd	Add support for network block devices
	nfs	Add support for NFS
gentoo-sources	ultra1	Enable if you have a SUN Ultra 1 with a HME interface
linux-docs	html	Install HTML documenation
mips-sources	cobalt	Enables support for Cobalt Microserver hardware (Qube2/RaQ2)
	impactdebug	Enables use of the Impact Early Console Hack. FOR DEBUGGING ONLY!
	ip27	Enables support for SGI Origin (IP27)
	ip28	Enables support for SGI Indigo2 Impact R10000 (IP28)
	ip30	Enables support for SGI Octane (IP30, 'Speedracer')
	ip32r10k	Enables experimental support for IP32 R10K kernels (SGI O2, 'Moosehead')
sparc-sources	ultra1	If you have a SUN Ultra 1 with a HME interface
zen-sources	drm-next	Enable the drm-next patch
zen-sources	stable	Clone stable git tree

sys-libs

Package	Flag	Description
glibc	erandom	Enable erandom/frandom support in glibc for ssp
	glibc-compat20	Enable the glibc-compat addon
	glibc-omitfp	Configure glibc with --enable-omitfp which lets the build system determine when it is safe to use -fomit-frame-pointer
	linuxthreads-tls	Configure the linuxthreads glibc with --with-_thread if supported by your system. --with-tls is always enabled if supported and is NOT controlled by this switch. So the glibc built will always support TLS binaries. This toggle chooses whether or not glibc itself uses TLS. If you're concerned about backwards compatibility with old binaries, leave this off.
	nptlonly	Disables building the linuxthreads fallback in glibc ebuilds that support building both linuxthread and nptl
	userlocales	Build only the locales specified in /etc/locales.build
libraw1394	juju	Use the new juju firewire stack in the Linux kernel
ncurses	ada	Add bindings for the ADA programming language
ncurses	trace	Enable test trace() support in ncurses calls
pam	audit	Enable support for sys-process/audit
talloc	compat	Enable extra compatibility stuff
tdb	tdbtest	Install tdbtest app
tdb	tools	Install extra tools
uclibc	pregen	Use pregenerated locales
	savedconfig	Adds support for user defined configs
	ssp	Force the use of ssp to be built into a hardened uclibc setup
	uclibc-compat	Build uclibc with backwards compatible options
	userlocales	Build only the locales specified in /etc/locales.build
	wordexp	Add support for word expansion (wordexp.h)

sys-power

Package	Flag	Description
acpid	logrotate	Use app-admin/logrotate for rotating logs
cpufreqd	nforce2	Enable support for nforce2 voltage settings plug-in
	nvidia	Enable nvidia overclocking (media-video/nvclock) plug-in
	pmu	Enable Power Management Unit plug-in
pm-utils	ntp	install support for net-misc/ntp
powerman	genders	Add support for selecting power control targets using genders (-g option)
powerman	httppower	Add support for HTTP based power controllers
suspend	crypt	Allows suspend and resume from encrypted disk
suspend	fbsplash	Add support for framebuffer splash

sys-process

Package	Flag	Description
cronie	inotify	Enable inotify filesystem monitoring support.
procps	n32	Enable n32 ABI support on mips

virtual

Package	Flag	Description
mpi	romio	Enable romio, a high-performance portable MPI-IO
poppler-utils	abiword	Enable support for app-office/abiword output. Requires dev-libs/libxml2.

www-apache

Package	Flag	Description
mod_mono	aspnet2	Handle all applications using ASP.NET 2.0 engine by default
mod_security	perl	Add a dependency upon Perl and install the script to update the Core Rule Set. Please note that this script will use the original Core Rule Set, and it's currently mostly untested.
mod_security	vanilla	Provide the original ModSecurity Core Rule Set without Gentoo-specific relaxation. When this flag is enabled, we install the unadulterated Core Rule Set. Warning! The original Core Rule Set is draconic and most likely will break your web applications, including Rails-based web applications and Bugzilla.
mod_suphp	checkpath	Check if script resides in DOCUMENT_ROOT
	mode-force	Run scripts with UID/GID specified in Apache configuration
	mode-owner	Run scripts with owner UID/GID
	mode-paranoid	Run scripts with owner UID/GID but also check if they match the UID/GID specified in the Apache configuration
mod_vhs	suphp	Enable www-apache/mod_suphp support
pwauth	domain-aware	Ignore leading domain names in username (Windows compat)
	faillog	Log failed login attempts
	ignore-case	Ignore string case in username (mostly Windows compat)

www-apps

Package	Flag	Description
Embperl	modperl	Enable www-apache/mod_perl support
Embperl	xalan	Enable dev-java/xalan support
bugzilla	extras	Optional Perl modules
bugzilla	modperl	Enable www-apache/mod_perl support
egroupware	gallery	Install gallery2 port for eGW
	icalsrv	Install iCal Server (eGroupware-iCalSrv)
	jpgraph	Add dev-php5/jpgraph support
	mydms	Install eGroupware-MyDMS
gallery	netpbm	Add media-libs/netpbm support
	unzip	Add app-arch/unzip support for the archive upload module
	zip	Add app-arch/zip for the zip download module
horde-passwd	clearpasswd	Enables cleartext password storage in the vpopmail files
lxr	freetext	Adds support for freetext search using swish-e
mediawiki	math	Ads math rendering support
mediawiki	restrict	Initial setup will only allow sysop user to create new accounts, read and edit any pages
rt	lighttpd	Add www-servers/lighttpd support
viewvc	cvsgraph	Add dev-util/cvsgraph support to show graphical views of revisions and branches
	highlight	Add app-text/highlight support to colourize code stored in the repository
	mod_python	Add www-apache/mod_python support
	pygments	Add dev-python/pygments support for syntax highlighting

www-client

Package	Flag	Description
chromium	ffmpeg	Add support for HTML5 audio/video tags via media-video/ffmpeg
elinks	bittorrent	Enable support for the BitTorrent protocol
	finger	Enable support for the finger protocol
	gopher	Enable support for the gopher protocol
epiphany	nss	Import passwords from older gecko based www-client/epiphany keyring.
icecat	custom-optimization	Fine-tune custom compiler optimizations
	mozdevelop	Enable features for web developers (e.g. Venkman)
	restrict-javascript	Pull in www-plugins/noscript extension to disable javascript globally, putting the user fully in control of the sites he/she visits
	sqlite	Enable/Disable system sqlite support
kazehakase	hyperestraier	enable hyperestraier support for full-text search in history
kazehakase	webkit	Use net-libs/webkit-gtk for rendering rather than net-libs/xulrunner
lynx	gnutls	Use gnutls library for HTTPS support (openssl is the default library for HTTPS support).
lynx	ssl	Enable HTTPS support.
midori	html	Install HTML documentation
midori	unique	Optional libunique support
mozilla-firefox	custom-optimization	Fine-tune custom compiler optimizations
	filepicker	Enable old gtkfilepicker from 1.0.x firefox
	iceweasel	Enable iceweasel branding
	mozdevelop	Enable features for web developers (e.g. Venkman)
	moznopango	Disable x11-libs/pango during runtime
	restrict-javascript	Pull in www-plugins/noscript extension to disable javascript globally, putting the user fully in control of the sites he/she visits
	xforms	XForms is a standard to split up XHTML into XForms, instance data, and user interface
mozilla-firefox-bin	restrict-javascript	Pull in x11-plugins/noscript extension to disable javascript globally, putting the user fully in control of the sites he/she visits
opera	ia32	Install 32-bit binaries instead of 64-bit binaries
opera	qt-static	Install binaries statically linked to Qt
seamonkey	custom-optimization	Fine-tune custom compiler optimizations
	mozdevelop	Enable features for web developers (e.g. Venkman)
	moznocompose	Disable building of mozilla's HTML editor component
	moznoirc	Disable building of mozilla's IRC client
	moznomail	Disable building mozilla's mail client
	moznopango	Disable x11-libs/pango during runtime
	moznoroaming	sroaming extension support
	restrict-javascript	Pull in www-plugins/noscript extension to disable javascript globally, putting the user full$ control of the sites he/she visits
	xforms	XForms is a standard to split up XHTML into XForms, instance data, and user interface
w3m	lynxkeymap	If you prefer Lynx-like key binding

www-misc

Package	Flag	Description
vdradmin-am	vdr	Support for media-video/vdr. Disable this if the VDR you want to control runs at a remote machine.
xxv	themes	Enable more themes via x11-themes/xxv-skins

www-plugins

Package	Flag	Description
adobe-flash	32bit	For amd64-multilib, installs the 32-bit plugin
adobe-flash	64bit	For amd64-multilib, installs the native 64-bit plugin
gnash	agg	Rendering based on the Anti-Grain Geometry Rendering Engine library
	cygnal	Enable building of the cygnal server
	ssh	Enable using SSH for network authentication in libnet

www-servers

Package	Flag	Description
apache	sni	Enable TLS Server Name Indication (SNI) - EXPERIMENTAL!
apache	suexec	Install suexec with apache
cherokee	admin	Install web based cherokee conf tool
cherokee	coverpage	Installs the default cherokee coverpage
fnord	auth	Enable HTTP authentication support
lighttpd	memcache	Enable memcache support for mod_cml and mod_trigger_b4_dl
	rrdtool	Enable rrdtool support via mod_rrdtool
	webdav	Enable webdav properties
nginx	addition	Enables HTTP addition filter module
	flv	Enables special processing module for flv files
	random-index	Enables HTTP random index module
	securelink	Enable HTTP secure link module
	status	Enables stub_status module
	sub	Enables sub_filter module
	webdav	Enable webdav support
ocsigen	ocamlduce	Enables ocamlduce XML typechecking for generated web pages
pound	dynscaler	Enable dynamic rescaling of back-end priorities
resin	admin	Enable Resin admin webapp
tomcat	admin	Enable Tomcat admin webapp

x11-apps

Package	Flag	Description
xdpyinfo	dmx	Builds support for Distributed Multiheaded X x11-base/xorg-server
xinit	consolekit	Enable consolekit integration for the privileges detection.

x11-base

Package	Flag	Description
xorg-server	dmx	Build the Distributed Multiheaded X server
	kdrive	Build the kdrive X servers
	tslib	Build with tslib support for touchscreen devices
	xorg	Build the Xorg X server (HIGHLY RECOMMENDED)

x11-drivers

Package	Flag	Description
ati-drivers	modules	Build the kernel modules
linuxwacom	modules	Build kernel module

x11-libs

Package	Flag	Description
agg	gpc	Enable gpc polygon clipper library
cairo	cleartype	Add ClearType-style behavior for sub-pixel hinting. Patch taken from Arch Linux
	glitz	Build with glitz support, which replaces some software render operations with Mesa OpenGL operations
	opengl	When used along with USE=glitz, enables glitz-glx usage. Requires hardware OpenGL support
fltk	games	Builds and installs some extra games
fltk	noxft	Disables xft; use for non-english characters
gtkdatabox	glade	Build with libglade and glade-3 supports, which includes a glade's module for GtkDataBox widget
gtkmathview	t1lib	Enable media-libs/t1lib support
libSM	uuid	Use UUID for session identification instead of IP address and system time.
libmatchbox	pango	Enable x11-libs/pango support
libmatchbox	xsettings	Enable the use of xsettings for settings management
libqxt	crypt	Enable support for blowfish encryption using dev-libs/openssl
	sql	Enable support for SQL databases using x11-libs/qt-sql
	web	Enable web support using dev-libs/fcgi
qt	immqt	Enable binary incompatible version of immodule for Qt
	immqt-bc	Enable binary compatible version of immodule for Qt
	kde	Select media-sound/phonon as phonon variant needed for kde
	qt3support	Enable the Qt3Support libraries for Qt4
qt-core	glib	Enable dev-libs/glib eventloop support
	optimized-qmake	Enable qmake optimization
	qt3support	Enable the Qt3Support libraries for Qt4. Note that this does not mean you can compile pure Qt3 programs with Qt4.
qt-gui	glib	Enable dev-libs/glib eventloop support
	qt3support	Enable the Qt3Support libraries for Qt4. Note that this does not mean you can compile pure Qt3 programs with Qt4.
	raster	Use the alternative raster graphicssystem as default rendering engine
qt-opengl	qt3support	Enable the Qt3Support libraries for Qt4
qt-qt3support	kde	Select media-sound/phonon as phonon variant needed for kde
qt-qt3support	phonon	Enable phonon configuration dialog in qtconfig
qt-sql	qt3support	Enable the Qt3Support libraries for Qt4
qt-webkit	kde	Select media-sound/phonon as phonon variant needed for kde
vte	glade	Provide integration with dev-util/glade.
wxGTK	gnome	Use gnome-base/libgnomeprintui for printing tasks.
	gstreamer	Enable the wxMediaCtrl class for playing audio and video through gstreamer.
	sdl	Use Simple Directmedia Layer (media-libs/libsdl) for audio.

x11-misc

Package	Flag	Description
adesklets	ctrlmenu	force CTRL to be pressed to fire context menu
fbpager	xrender	Enable transparency support via x11-libs/libXrender
google-gadgets	soup	Enables XML HTTP request extension based on net-libs/libsoup
google-gadgets	webkit	Enables browser element and script runtime based on net-libs/webkit-gtk
rednotebook	libyaml	enable libyaml support
shutter	drawing	Enables drawing tool
shutter	webphoto	Enables screenshots of websites
slim	screenshot	Enable screenshot support (using media-gfx/imagemagick)
tint2	battery	Enable battery status plugin
tint2	examples	Install tint2rc examples
vnc2swf	x11vnc	Install script that depends on x11vnc
x11vnc	system-libvncserver	Build x11vnc against the system libvncserver (experimental)
xfce4-notifyd	libsexy	Enable support for x11-libs/libsexy
xlockmore	xlockrc	Enables xlockrc for people without PAM
xscreensaver	new-login	Enables New Login button using gdmflexiserver (gnome-base/gdm)
zim	screenshot	Enable screenshot support (using media-gfx/scrot)

x11-plugins

Package	Flag	Description
bfm	gkrellm	Enable building of app-admin/gkrellm module
gkrellm-plugins	audacious	Enable the audacious plugin x11-plugins/gkrellmms
gkrellmbups	nut	Enable monitoring Network-UPS via sys-power/nut
purple-plugin_pack	talkfilters	Enable support for app-text/talklfilters
screenlets	svg	Highly Recommended: Enable SVG graphics via dev-python/librsvg-python
wmhdplop	gkrellm	Enable building of app-admin/gkrellm module
wmsysmon	high-ints	Enable support for monitoring 24 interrupts. Useful on SMP machines

x11-terms

Package	Flag	Description
aterm	background	Enable background image support via media-libs/libafterimage
aterm	xgetdefault	Enable resources via X instead of aterm small version
eterm	escreen	Enable built-in app-misc/screen support
hanterm	utempter	Records user logins. Useful on multi-user systems
mlterm	scim	Enable scim support
mlterm	uim	Enable uim support
mrxvt	menubar	Enable mrxvt menubar
mrxvt	utempter	REcords user logins. Useful on multi-user systems
rxvt	linuxkeys	Define LINUX_KEYS (changes Home/End key)
rxvt	xgetdefault	Enable resources via X instead of rxvt small version
rxvt-unicode	afterimage	Enable support for media-libs/libafterimage
	iso14755	Enable ISO-14755 support
	wcwidth	Enable wide char width support
	xterm-color	Enable xterm 256 color support
xterm	toolbar	Enable the xterm toolbar to be built

x11-themes

Package	Flag	Description
gentoo-artwork	grub	Install extra sys-boot/grub themes
	icons	Install icons
	lilo	Install extra sys-boot/lilo themes
	pixmaps	Install pixmaps
gtk-engines-murrine	animation-rtl	Progressbar animation from right to left
gtk-engines-murrine	themes	Pull in themes via x11-themes/murrine-themes
gtk-engines-nodoka	animation-rtl	Progressbar animation from right to left
gtk-engines-qt	gnome	Enable proper theming of buttons in gnome toolbars (as opposed to just plain gtk+ toolbars)
gtk-engines-qtcurve	firefox3	Install GUI theme tweaks for version 3 of www-client/mozilla-firefox
gtk-engines-qtcurve	mozilla	Install GUI theme tweaks for mozilla based browsers, including version 2 of www-client/mozilla-firefox
qtcurve-qt4	kde	Enable KDE4 support. This adds a QtCurve configuration module to KDE's SystemSettings.
redhat-artwork	audacious	Install media-sound/audacious theme
	cursors	Install Bluecurve cursors
	gdm	Install Bluecurve gnome-base/gdm theme
	icons	Install Bluecurve icons
	kdm	Install Bluecurve kde-base/kdm theme
	nautilus	Install Bluecurve gnome-base/nautilus icons
skinenigmang-logos	dxr3	Install logos for lower osd color depth on dxr3 cards

x11-wm

Package	Flag	Description
compiz	fuse	Enables support for the filesystem in userspace plugin through sys-fs/fuse.
compiz-fusion	emerald	Install the x11-wm/emerald package.
compiz-fusion	unsupported	Install the x11-plugins/compiz-fusion-plugins-unsupported package.
enlightenment	pango	Enable pango font rendering
enlightenment	xrandr	Enable support for the X xrandr extension
fluxbox	disableslit	Disables the fluxbox slit (or dock)
	disabletoolbar	Disables the fluxbox toolbar
	slit	Enables the fluxbox slit (or dock)
	toolbar	Enables the fluxbox toolbar
fvwm	gtk2-perl	Enable GTK2 Perl bindings
	lock	Enable screen locking
	netpbm	Enable NetPBM support (used by FvwmScript-ScreenDump)
	rplay	Enable rplay support
	stroke	Mouse Gesture support
matchbox-common	pda	Support for pda folders
matchbox-desktop	dnotify	Use the linux kernel directory notification feature.
matchbox-panel	dnotify	Use the linux kernel directory notification feature.
matchbox-panel	lowres	Optimize for low resolution screens.
musca	apis	Optionally install the experimental `apis' window manager
ratpoison	history	Use sys-libs/readline for history handling
sawfish	pango	Enable pango support
stumpwm	clisp	Use CLISP for the runtime
stumpwm	sbcl	Use SBCL for the runtime
vtwm	rplay	Enable rplay support, needed for sound.
windowmaker	modelock	Enable XKB language status lock support. README says: "If you don't know what it is you probably don't need it."
windowmaker	vdesktop	Enable dynamic virtual desktop (conflicts with software that works on the edges of the screen)

xfce-base

Package	Flag	Description
libxfce4ui	glade	Build support for Glade 3's GtkBuilder implementation
libxfcegui4	glade	Build glade bindings
thunar	trash-plugin	Build Trash plug-in for panel
xfce-utils	lock	Enable screen locking
xfce4-session	fortune	Install tips and tricks app (xfce4-tips), adds dependency on games-misc/fortune-mod
xfce4-session	gnome-keyring	Support for storing your password.
xfce4-settings	keyboard	Enable Keyboard layout selection with x11-libs/libxklavier
xfce4-settings	sound	Enable sound event support with media-libs/libcanberra
xfdesktop	menu-plugin	Build Menu plug-in for panel
xfdesktop	thunar	Build support for application launchers using xfce-base/thunar

xfce-extra

Package	Flag	Description
thunar-thumbnailers	grace	Enable support for sci-visualization/grace thumbnails
thunar-vcs-plugin	git	Enable dev-util/git support
xfce4-mpc-plugin	libmpd	Build using media-libs/libmpd backend, instead of native fallback which is preferred
xfce4-playercontrol-plugin	audacious	Enable Audacious support
xfce4-playercontrol-plugin	mpd	Enable Music Player Daemon support
xfce4-power-manager	dpms	Build with DPMS support
xfce4-power-manager	plugins	Build panel plugins
xfce4-screenshooter	zimagez	Optional support to host screenshots on ZimageZ, a free online image service

Updated November 23, 2009

Summary: Global and local USE flags used by Gentoo

Xavier Neys

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