# Copyright 1999-2007 Gentoo Foundation.
# Distributed under the terms of the GNU General Public License v2
# $Header: /var/cvsroot/gentoo-x86/profiles/use.local.desc,v 1.3047 2007/09/28 16:54:34 drac Exp $

# This file contains descriptions of local USE flags, and the ebuilds which
# contain them.

# Keep it sorted.

app-accessibility/festival:asterisk - adds a new command named tts_textasterisk that is required by net-misc/asterisk to communicate with the Festival server
app-accessibility/festival:mbrola - Adds support for mbrola voices
app-accessibility/freetts:jsapi - build Java Speech API (JSAPI) support
app-accessibility/freetts:mbrola - Adds support for mbrola voices
app-accessibility/gnome-speech:freetts - Adds support for the freetts speech driver
app-accessibility/gnopernicus:brltty - Adds support for braille displays using brltty
app-accessibility/speech-dispatcher:flite - Adds support for flite speech engine.
app-admin/conky:audacious - enable monitoring of audio tracks that are playing (media-sound/audacious)
app-admin/conky:bmpx - enable monitoring of audio tracks that are playing (media-sound/bmpx)
app-admin/conky:hddtemp - enable monitoring of hdd temperature (app-admin/hddtemp)
app-admin/conky:mpd - enable monitoring mpd controlled music  (media-sound/mpd)
app-admin/diradm:automount - Support for automount data in LDAP
app-admin/diradm:irixpasswd - Support for storing separate IRIX passwords
app-admin/gkrellm:hddtemp - enable monitoring of hdd temperature (app-admin/hddtemp)
app-admin/gnome-system-tools:nfs - Adds support for NFS shares
app-admin/lcap:lids - If you have the Linux Intrusion Detection System
app-admin/prelude-manager:tcpwrapper - Add support for tcp_wrappers
app-admin/sdsc-syslog:beep - Use beep libraries (net-libs/roadrunner)
app-admin/sshguard:ipfilter - Enable ipfilter firewall support (only for *bsd)
app-admin/syslog-ng:spoof-source - Enable support for spoofed source addresses
app-admin/testdisk:ntfs - Include the ability to read NTFS filesystems
app-admin/testdisk:reiserfs - include reiserfs reading ability
app-admin/webalizer:search - Include the search patch
app-admin/webalizer:xtended - Include the 404 extension
app-admin/webmin:webmin-minimal - Install the minimal webmin distribution
app-antivirus/clamav:logrotate - Install logrotate script for clamav logs
app-arch/dump:ermt - encrypted rmt support
app-arch/libarchive:xattr - if you want extended attributes enabled
app-arch/pdv:nomotif - Disable motif frontend.
app-backup/amanda:xfs - Support for backing up raw XFS filesystems using xfsdump
app-backup/bacula:bacula-clientonly - Disable DB support, and just build a client
app-backup/bacula:bacula-console - Build console only bits, no gui
app-backup/bacula:bacula-nodir - Disable building of director in 1.38.x and later.
app-backup/bacula:bacula-nosd - Disable building of storage daemon in 1.38.x and later.
app-backup/bacula:bacula-split-init - Use separate init scripts for fd/sd/dir
app-backup/bacula:client-only - Disable DB support, and just build a client
app-backup/bacula:logrotate - Install support files for logrotate
app-backup/bacula:logwatch - Install support files for logwatch
app-backup/boxbackup:client-only - Disable server support, and just build a client
app-backup/dar:dar32 - Enables --enable-mode=32 option, which replace infinint by 32 bits integers.
app-backup/dar:dar64 - Enables --enable-mode=64 option, which replace infinint by 64 bits integers.
app-backup/kdar:dar32 - Support libdar32.so to use.
app-backup/kdar:dar64 - Support libdar64.so to use.
app-backup/rdiff-backup:xattr - if you want extended attributes enabled
app-benchmarks/bootchart:acct - Enable process accounting
app-benchmarks/jmeter:beanshell - Enable BeanShell scripting support
app-cdr/brasero:beagle - Enable Beagle support for searches.
app-cdr/brasero:gdl - Enable gld support for customisable GUI.
app-cdr/brasero:libburn - Enable libburn backend.
app-cdr/brasero:totem - Enable support for Totem playlists.
app-cdr/cdrdao:pccts - Use dev-util/pccts instead of the built-in substitution.
app-cdr/cdrkit:hfs - Provide building of HFS (Apple) CD-images
app-cdr/disc-cover:cdrom - Enable audio CD support. This is not needed to make www-apps/disc-cover work.
app-cdr/k3b:css - Enables ripping of encrypted dvds
app-cdr/k3b:emovix - Enable burning support for eMoviX images
app-cdr/pxlinux:gnuplot - enable gnuplot support
app-cdr/serpentine:muine - Enable Muine support
app-crypt/ccid:nousb - Disable USB support via pcsc-lite
app-crypt/ccid:twinserial - Enable twinserial reader
app-crypt/gnupg:ecc - Use elliptic curve cryptosystem patch
app-crypt/gnupg:gpg2-experimental - Install experimental development version of gnupg
app-crypt/gnupg:idea - Use the patented IDEA algorithm
app-crypt/gnupg:openct - build using dev-libs/openct compatibility
app-crypt/gnupg:pcsc-lite - build with pcsc-lite
app-crypt/gringotts:suid - Install the binary suid, acknowledging the usual risks
app-crypt/ophcrack:ophsmall - Makes use of smaller cracking tables
app-crypt/seahorse:gedit - Enable the gedit plugin
app-crypt/seahorse:keyring - Enable support for gnome-keyring
app-crypt/seahorse:nautilus - Add support for nautilus file manager
app-dicts/aspell-be:classic - Support classic spelling by default
app-doc/doxygen:nodot - removes graphviz dependency, along with dot graphs
app-doc/gimp-help:webinstall - optimize images for web installation (fewer colors, depends on imagemagick)
app-editors/cssed:plugin - Install plugin development files
app-editors/emacs-cvs:gzip-el - Compress bundled Emacs Lisp source
app-editors/emacs-cvs:hesiod - Enable support for hesiod
app-editors/emacs-cvs:sound - Enable sound
app-editors/emacs-cvs:toolkit-scroll-bars - Use the selected toolkit's scrollbars in preference to Emacs' own scrollbars
app-editors/emacs-cvs:xft - Build Emacs with support for the XFT font renderer (ie. the XFT_JHD_BRANCH branch from CVS)
app-editors/emacs:gzip-el - Compress bundled Emacs Lisp source
app-editors/emacs:hesiod - Enable support for hesiod
app-editors/emacs:nosendmail - If you do not want to install any MTA
app-editors/emacs:sound - Enable sound
app-editors/emacs:toolkit-scroll-bars - Use the selected toolkit's scrollbars in preference to Emacs' own scrollbars
app-editors/gvim:aqua - Include support for the Aqua / Carbon GUI
app-editors/gvim:netbeans - Include netbeans integration support
app-editors/gvim:nextaw - Include support for the neXtaw GUI
app-editors/jasspa-microemacs:nanoemacs - Build NanoEmacs instead of MicroEmacs
app-editors/joe:xterm - Enable full xterm clipboard support
app-editors/jove:unix98 - Use the Unix98 pty's instead of the BSD pts's
app-editors/katoob:highlight - Enable source code highlighting
app-editors/nano:justify - Toggle the justify option ...
app-editors/nvu:moznoxft - placeholder until mozilla eclass is modified for nvu
app-editors/tea:enchant - Enable spell checking using enchant
app-editors/tea:hacking - Enable hacking support...
app-editors/tea:sounds - Enable sound support
app-editors/vim:vim-pager - Install vimpager and vimmanpager links
app-editors/vim:vim-with-x - Link console vim against X11 libraries to enable title and clipboard features in xterm
app-editors/xemacs:athena - Chooses the MIT Athena widget set
app-editors/xemacs:dnd - Enables support for the x11-libs/dnd drag-n-drop library
app-editors/xemacs:eolconv - Support detection and translation of newline conventions.
app-editors/xemacs:pop - Support POP for mail retrieval.
app-editors/xemacs:xim - Enable X11 XiM input method
app-emacs/auctex:preview-latex - Use bundled preview-latex
app-emacs/delicious:planner - Include support for app-emacs/planner
app-emacs/easypg:gnus - Include support for the Gnus newsreader
app-emacs/remember:bbdb - Include support for app-emacs/bbdb
app-emacs/remember:planner - Include support for app-emacs/planner
app-emacs/vm:bbdb - Include support for app-emacs/bbdb
app-emacs/wanderlust:bbdb - Include support for app-emacs/bbdb
app-emulation/bochs:debugger - Enable the bochs debugger
app-emulation/bochs:vnc - Enable vnc support
app-emulation/e-uae:capslib - Add CAPS library support
app-emulation/e-uae:sdl-sound - Use media-libs/sdl-sound for audio output
app-emulation/emul-linux-x86-glibc:nptlonly - Disables installing the linuxthreads fallback in glibc ebuilds that support building both linuxthreads and nptl.
app-emulation/emul-linux-x86-qtlibs:immqt-bc - Enable binary compatible version of immodule for Qt
app-emulation/fuse:libdsk - Enable support for the floppy disk emulation library
app-emulation/hercules:custom-cflags - Use CFLAGS from /etc/make.conf rather than the default package CFLAGS (not supported)
app-emulation/libvirt:qemu - Add support for QEMU/KVM-based virtual machines
app-emulation/libvirt:xen - Add support for Xen-based virtual machines
app-emulation/mol:oldworld - Includes Macintosh's OldWorld support
app-emulation/mol:pci - Experimental PCI proxy support
app-emulation/mol:sheep - Support for the sheep net driver
app-emulation/mol:vnc - Includes vnc support
app-emulation/pearpc:jit - Use the JITC-X86 CPU
app-emulation/point2play:emerald - For people who are in the Transgaming Emerald Club
app-emulation/qemu-softmmu:kqemu - Enables the kernel module acceleration on the x86 cpu
app-emulation/uade:audacious - Enables support for media-sound/audacious
app-emulation/uae:scsi - Enable the uaescsi.device
app-emulation/uae:sdl-sound - Use libsdl for audio output
app-emulation/uae:ui - Build User Interface (could be gtk or ncurses based, depending on sdl, dga, svga, and aalib USE flags)
app-emulation/vice:resid - Enable support for ReSID
app-emulation/virtualbox-bin:additions - Install Guest System Tools ISO
app-emulation/virtualbox-bin:nowrapper - Disable the VirtualBox XPCom Server autostart wrapper
app-emulation/virtualbox-bin:sdk - Enable building of SDK
app-emulation/virtualbox:additions - Install Guest System Tools ISO
app-emulation/virtualbox:alsa - Enable support for ALSA instead of OSS
app-emulation/virtualbox:nowrapper - Disable the VirtualBox XPCom Server autostart wrapper
app-emulation/virtualbox:sdk - Enable building of SDK
app-emulation/virtualbox:vboxbfe - Install simple SDL frontend useful for debugging purposes
app-emulation/virtualbox:vditool - Install the Virtual Disk Image Manager vditool
app-emulation/xen-tools:custom-cflags - Use CFLAGS from /etc/make.conf rather than the default Xen CFLAGS (not supported)
app-emulation/xen-tools:hvm - Enable support for hardware based virtualization (VT-x, AMD-v)
app-emulation/xen-tools:pygrub - Install the pygrub boot loader
app-emulation/xen-tools:screen - Enable support for running domain U consoles in a screen session
app-emulation/xen-tools:ioemu - Enable support for emulated io devices including video via VNC for domainUs
app-emulation/xen:custom-cflags - Use CFLAGS from /etc/make.conf rather than the default Xen CFLAGS (not supported)
app-emulation/xen:pae - Enable support for PAE kernels (usually x86-32 with >4GB memory)
app-forensics/aide:xattr - if you want extended attributes enabled
app-forensics/samhain:login-watch - Compile in the module to watch for login/logout events
app-forensics/samhain:mounts-check - Compile in the module to check for correct mount options
app-forensics/samhain:netclient - Compile a client, rather than a standalone version
app-forensics/samhain:netserver - Compile a server, rather than a standalone version
app-forensics/samhain:suidcheck - Compile in the module to check file system for SUID/SGID binaries
app-forensics/samhain:userfiles - Compile in the module to check for files in user home directories
app-forensics/sleuthkit:dbtool - Add patch for dbtool interface from PyFlag
app-i18n/anthy:ucs4 - Enable ucs4 support
app-i18n/atokx2:ext-iiimf - Link with the system IIIMF, rather than the bundled version
app-i18n/im-ja:anthy - Support for Anthy input method
app-i18n/im-ja:skk - Support for SKK input method
app-i18n/kimera:anthy - Support for Anthy input method
app-i18n/scim-cvs:immqt - Enable immodule for Qt support (binary incompatible)
app-i18n/scim-cvs:immqt-bc - Enable immodule for Qt support (binary compatible)
app-i18n/tomoe:hyperestraier - Enable hyperestraier support
app-i18n/tomoe:subversion - Enable subversion support
app-i18n/uim-svn:anthy - Enable anthy support
app-i18n/uim-svn:dict - Build uim-dict (a dictionary utility for uim)
app-i18n/uim-svn:eb - Enable EB support
app-i18n/uim-svn:fep - Build uim-fep
app-i18n/uim-svn:immqt - Enable immodule for Qt support
app-i18n/uim:anthy - Support for Anthy input method
app-i18n/uim:eb - Enable EB support
app-i18n/uim:prime - Enable PRIME support
app-laptop/pbbuttonsd:ibam - Enable support for Intelligent Battery Monitoring
app-laptop/pbbuttonsd:macbook - Enable support for the Macbook and Macbook Pro
app-laptop/tp_smapi:hdaps - Install a compatible HDAPS module
app-laptop/tpctl:tpctlir - enable support for thinkpad models 760 and 765
app-misc/beagle:chm - Enable indexing of MS HTML Help files (.chm)
app-misc/beagle:galago - Enable desktop presence via galago
app-misc/beagle:ole - Enable ole support
app-misc/beagle:thunderbird - Enable Mozilla Thunderbird indexing
app-misc/booh:transcode - Use transcode to extract video thumbnails
app-misc/digitemp:ds2490 - Build support for the ds2490 sensor
app-misc/digitemp:ds9097 - Build support for the ds9097 sensor
app-misc/digitemp:ds9097u - Build support for the ds9097u sensor
app-misc/g15composer:amarok - Enable display of titles played in Amarok
app-misc/gpsdrive:garmin - Adds specific support for Garmin GPS receivers
app-misc/graphlcd-base:g15 - Add support for g15daemon driver ( e.g Logitech G15 Keybord )
app-misc/lcd-stuff:mpd - Add support for display of mpd controlled music
app-misc/lcd-stuff:rss - Add support for display of RSS feeds
app-misc/lcd4linux:mpd - Add support for display of mpd controlled music
app-misc/lcdproc:irman - Enable support for IRMan
app-misc/lcdproc:nfs - Adds support for NFS file system
app-misc/lcdproc:seamless-hbars - Try to avoid gaps in horizontal bars
app-misc/lirc:hardware-carrier - The transmitter device generates its clock signal in hardware
app-misc/lirc:transmitter - add transmitter support to some lirc-drivers (e.g. serial)
app-misc/mc:7zip - add support for 7zip archives
app-misc/note:general - add support for ascii flatfile backend
app-misc/note:text - add support for text backend
app-misc/pal:ical - Add support for converting ical format to pal
app-misc/roadnav:festival - Enable festival support
app-misc/roadnav:openstreetmap - Enable openstreetmap support
app-misc/roadnav:scripting - Enable scripting support
app-misc/screen:multiuser - Enable multiuser support (by setting correct permissions)
app-misc/screen:nethack - Express error messages in nethack style
app-misc/tablix:pvm - Add support for parallel virtual machine (http://www.epm.ornl.gov/pvm/pvm_home.html)
app-misc/tomboy:galago - Add support for the galago desktop presence framework
app-misc/towitoko:moneyplex - Makes libtowitoko work for the moneyplex home banking software
app-misc/tracker:applet - Enable deskbar applet support
app-misc/tracker:gsf - Enable libgsf based data extractor
app-misc/tracker:thumbnailing - Enable thumbnail generation
app-misc/worker:avfs - Enable avfs support
app-misc/workrave:distribution - Enable networking. See http://www.workrave.org/features/
app-mobilephone/gammu:irda - Enable infrared support
app-mobilephone/gnokii:ical - Enable libical support
app-mobilephone/gnokii:irda - Enable infrared support
app-mobilephone/gnokii:sms - Enable SMS support (build smsd)
app-mobilephone/kmobiletools:gammu - Enable the Gammu backend.
app-mobilephone/kmobiletools:obex - Enable obex transports.
app-mobilephone/obexftp:swig - Enable rebuild of swig bindings
app-mobilephone/smstools:stats - Enable statistic reporting
app-mobilephone/yaps:capi - Enable CAPI support
app-office/abiword-plugins:grammar - Enable grammar checking via grammar-link
app-office/abiword-plugins:math - Enable gtkmathview support
app-office/abiword-plugins:ots - Enable Text Summarizer plugin
app-office/abiword-plugins:thesaurus - Enable thesaurus support
app-office/abiword-plugins:wordperfect - Enable wordperfect file support via libwpd
app-office/dia:gnome-print - Gnome-Print support
app-office/gnucash:chipcard - Enable support for chipcard reading and processing.
app-office/gnucash:hbci - Enable HBCI support, for connecting to some internet banks
app-office/gnucash:quotes - Enable Online Stock Quote retrieval.
app-office/grisbi:print - Enable TeX and printing support
app-office/imposter:iksemel - Enable externel iksemel parsing support.
app-office/kmymoney2:hbci - Adds HBCI online banking support
app-office/ledger:gnuplot - Enable gnuplot support
app-office/mozilla-sunbird:moznopango - Disable pango during runtime
app-office/openoffice:binfilter - Enable support for legacy StarOffice 5.x and earlier file formats
app-office/openoffice:branding - Enable Gentoo branded splash screen
app-office/openoffice:odk - Build the Office Development Kit
app-office/openoffice:sound - Enable sound support through portaudio and libsndfile
app-office/openoffice:webdav - Enable webdav support
app-office/rabbit:enscript - enscript support
app-office/rabbit:gnome-print - Gnome-Print support
app-office/rabbit:gs - Ghostscript support
app-office/rabbit:tgif - tgif support
app-office/tpp:figlet - Installs app-misc/figlet to support the --huge command
app-pda/libopensync-plugin-irmc:irda - Enable IrDA support.
app-pda/libopensync-plugin-syncml:http - Enable http transports.
app-pda/libopensync-plugin-syncml:obex - Enable obex transports.
app-pda/libsyncml:http - Enable http transports.
app-pda/libsyncml:obex - Enable obex transports.
app-pda/multisync:gnokii - Address synchronization with mobile phones via Gnokii.
app-pda/multisync:irmc - Adds support for Mobile Client synchronization via IrDa/IrMC/Bluetooth (eg: SonyEricsson T39/T68i)
app-pda/multisync:kdepim - Adds support for KDEPIM sync.
app-pda/multisync:nokia6600 - Adds support for Nokia 6600.
app-pda/synce-kde:avantgo - Adds support for syncing Avantgo accounts.
app-portage/conf-update:colordiff - Use colors when displaying diffs
app-portage/portato:userpriv - Allow emerge processes as normal user
app-shells/bash:bashlogger - Log ALL commands typed into bash; should ONLY be used in restricted environments such as honeypots
app-shells/bash:plugins - Add support for loading builtin's at runtime via `enable`
app-shells/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.
app-shells/scsh-install-lib:scsh - Use a non-FHS directory layout.
app-shells/scsh:scsh - Use a non-FHS directory layout.
app-shells/shish:diet - Use dietlibc
app-shells/tcsh:catalogs - Adds support for NLS catalogs
app-shells/zsh:cap - Adds POSIX.1e (formerly POSIX 6) capabilities for zsh
app-text/crm114:mew - Add support for using the mewdecode mime decoder.
app-text/crm114:mimencode - Adds support for using the mimencode mime
app-text/crm114:normalizemime - Add support for using the normalizemime
app-text/estraier:kakasi - Enable kakasi support for Estraier
app-text/estraier:mecab - Enable mecab support for Estraier
app-text/evince:djvu - Enable djvu viewer support for Evince
app-text/evince:dvi - Enable the built-in DVI viewer for Evince
app-text/evince:nautilus - Enable the nautilus plugin
app-text/evince:t1lib - Enable the Type-1 fonts for the built-in DVI viewer for Evince
app-text/ghostscript-esp:djvu - Enable gsdjvu support
app-text/ghostscript-gpl:djvu - Enable gsdjvu support
app-text/hyperestraier:mecab - Enable mecab support for Estraier
app-text/namazu:kakasi - Enable kakasi support for namazu
app-text/noweb:icon - Enable icon language support for noweb
app-text/pdftk:nodrm - Decrypt a document with the user_pw even if it has an owner_pw set
app-text/sword-modules:intl - Enable different languages
app-text/sword:icu - Enable icu support for sword
app-text/sword:lucene - Enable lucene support for faster searching
app-text/webgen:markdown - Markdown support
app-text/webgen:textile - Textile support
app-text/webgen:thumbnail - Thumbnail creation support using rmagick
app-text/xpdf:nodrm - Disable the drm feature decoder.
app-vim/gentoo-syntax:ignore-glep31 - Remove GLEP 31 (UTF-8 file encodings) settings
app-vim/vcscommand:cvs - Enable CVS support
app-vim/vcscommand:subversion - Enable subversion support
app-vim/vcscommand:svk - Enable SVK support
dev-cpp/sptk:excel - Enable Excel support
dev-db/libpq:pg-intdatetime - Enables --enable-integer-datetimes configure option, which changes PG to use 64-bit integers for timestamp storage.
dev-db/mysql-community:big-tables - Make tables contain up to 1.844E+19 rows
dev-db/mysql-community:cluster - Add support for NDB clustering.
dev-db/mysql-community:embedded - Build embedded server (libmysqld)
dev-db/mysql-community:extraengine - Add support for alternative storage engines.
dev-db/mysql-community:latin1 - Use LATIN1 encoding instead of UTF8.
dev-db/mysql-community:max-idx-128 - Raise the max index per table limit from 64 to 128
dev-db/mysql-community:minimal - Install client programs only, no server
dev-db/mysql-community:pbxt - Add experimental support for pbxt storage engine
dev-db/mysql-gui-tools:administrator - Build and install MySQL Administrator
dev-db/mysql-gui-tools:query-browser - Build and install MySQL Query Browser
dev-db/mysql-gui-tools:workbench - Build and install MySQL Workbench
dev-db/mysql:big-tables - Make tables contain up to 1.844E+19 rows
dev-db/mysql:cluster - Add support for NDB clustering.
dev-db/mysql:embedded - Build embedded server (libmysqld)
dev-db/mysql:extraengine - Add support for alternative storage engines.
dev-db/mysql:latin1 - Use LATIN1 encoding instead of UTF8.
dev-db/mysql:max-idx-128 - Raise the max index per table limit from 64 to 128
dev-db/mysql:minimal - Install client programs only, no server
dev-db/mysql:raid - deprecated option, removed in the 5.0 series
dev-db/pgcluster:pg-intdatetime - Enables --enable-integer-datetimes configure option, which changes PG to use 64-bit integers for timestamp storage.
dev-db/postgis:geos - Add the GEOS library for exact topological tests.
dev-db/postgis:proj - Add the Proj library for reprojection features.
dev-db/postgresql:pg-intdatetime - Enables --enable-integer-datetimes configure option, which changes PG to use 64-bit integers for timestamp storage.
dev-db/rekall:xbase - Support for the Xbase db family, covering dBase, Clipper, FoxPro, Visual dBase/Objects/FoxPro plus some older products.
dev-db/sqlite:nothreadsafe - turn off thread safe operation of sqlite
dev-db/sqlite:soundex - Enable the soundex function to compute soundex encodings of strings
dev-db/tora:oci8-instant-client - Use dev-db/oracle-instantclient-basic as Oracle provider instead of requiring a full Oracle server install
dev-embedded/ponyprog:epiphany - Enable epiphany support
dev-games/cegui:devil - image loading support with DevIL
dev-games/cegui:xerces-c - use external Xerces-C++ XML parser instead of tiny embedded XML parser
dev-games/crystalspace:3ds - Enables support for .3DS files in CrystalSpace
dev-games/crystalspace:cal3d - include support for skeleton animation
dev-games/crystalspace:cegui - include support for Crazy Eddie GUI
dev-games/crystalspace:cg - NVIDIA toolkit plugin
dev-games/crystalspace:ode - include support for Open Dynamics Engine
dev-games/guichan:allegro - Build the Allegro frontend
dev-games/ode:double-precision - more precise calculations at the expense of speed
dev-games/ode:nogyroscopic - disable gyroscopic term maybe improving stability
dev-games/ode:noopcode - disable OPCODE (trimesh support)
dev-games/ogre:cegui - build the CEGUI samples
dev-games/ogre:cg - NVIDIA toolkit plugin
dev-games/ogre:devil - image loading support with DevIL
dev-games/ogre:double-precision - more precise calculations at the expense of speed
dev-haskell/gtk2hs:glade - Enable libglade bindings compilation
dev-java/ant-tasks:jai - Enable JAI (Java Imaging) Ant task
dev-java/ant-tasks:javamail - Enable JavaMail Ant task
dev-java/ant-tasks:noantlr - Disable ANTLR Ant task -- Warning: Enabling this could break some of the Java packages!!
dev-java/ant-tasks:nobcel - Disable bcel Ant task -- Warning: Enabling this could break some of the Java packages!!
dev-java/ant-tasks:nobeanutils - Disable beanutils Ant task -- Warning: Enabling this could break some of the Java packages!!
dev-java/ant-tasks:nobsf - Disable bsf Ant task -- Warning: Enabling this could break some of the Java packages!!
dev-java/ant-tasks:nobsh - Disable bsh Ant task -- Warning: Enabling this could break some of the Java packages!!
dev-java/ant-tasks:nocommonslogging - Disable commons-logging Ant task -- Warning: Enabling this could break some of the Java packages!!
dev-java/ant-tasks:nocommonsnet - Disable commons-net Ant task -- Warning: Enabling this could break some of the Java packages!!
dev-java/ant-tasks:nojdepend - Disable Jdepend Ant task -- Warning: Enabling this could break some of the Java packages!!
dev-java/ant-tasks:nojmf - Disable JMF (Java Media Framework) Ant task -- Warning: Enabling this could break some of the Java packages!!
dev-java/ant-tasks:nojsch - Disable Jsch Ant task -- Warning: Enabling this could break some of the Java packages!!
dev-java/ant-tasks:nojython - Disable Jython Ant task -- Warning: Enabling this could break some of the Java packages!!
dev-java/ant-tasks:nolog4j - Disable Apache log4j Ant task -- Warning: Enabling this could break some of the Java packages!!
dev-java/ant-tasks:nooro - Disable Oro Ant task -- Warning: Enabling this could break some of the Java packages!!
dev-java/ant-tasks:noregexp - Disable Apache Regexp Ant task -- Warning: Enabling this could break some of the Java packages!!
dev-java/ant-tasks:noresolver - Disable Apache Resolver Ant task -- Warning: Enabling this could break some of the Java packages!!
dev-java/ant-tasks:norhino - Disable Rhino Ant task -- Warning: Enabling this could break some of the Java packages!!
dev-java/ant-tasks:noswing - Disable Swing Ant task -- Warning: Enabling this could break some of the Java packages!!
dev-java/ant-tasks:noxalan - Disable Xalan Ant task -- Warning: Enabling this could break some of the Java packages!!
dev-java/ant-tasks:noxerces - Disable Xerces Ant task -- Warning: Enabling this could break some of the Java packages!!
dev-java/antlr:nojava - Disable support for Java code backend
dev-java/antlr:script - Install a script to run antlr
dev-java/aspectwerkz:java5 - Enable Java 5 specific features
dev-java/avalon-logkit:javamail - Enable support for javamail
dev-java/avalon-logkit:jms - Enable support for JMS (Java Message Service)
dev-java/backport-util-concurrent:java5 - Enable also the 1.6 > 1.5 backport.
dev-java/bsf:jython - Enable Jython support
dev-java/bsf:rhino - Enable Rhino support
dev-java/bsh:bsf - Enable support for Apache Bean Scripting Framework
dev-java/commons-collections:test-framework - Install the test framework
dev-java/commons-logging:avalon-framework - Add optional support for avalon-framework
dev-java/commons-logging:avalon-logkit - Add optional support for avalon-logkit
dev-java/commons-logging:log4j - Add optional support for log4j
dev-java/commons-logging:servletapi - Add optional support for servletapi
dev-java/commons-modeler:commons-digester - Add support for the commons-digester based Mbeans Descriptor source
dev-java/diablo-jdk:jce - Enable Java Cryptographic Extension Unlimited Strength Policy files
dev-java/fop:hyphenation - Precompile hyphenation patterns from the dev-java/offo-hyphenation package and install them as fop-hyph.jar
dev-java/fop:jai - Enable jai support
dev-java/fop:jimi - Enable jimi support
dev-java/gjdoc:xmldoclet - Also build support for the xml doclet that generates output in xml instead of the traditional html javadoc.
dev-java/gnu-classpath:dssi - Enable the DSSI midi synthesizer provider
dev-java/gnu-classpath:gconf - Enable the GConf based util.peers backend
dev-java/groovy:bsf - Enable support for Apache Bean Scripting Framework
dev-java/ibm-jdk-bin:javacomm - Enable Java Communications API support
dev-java/jamvm:ffi - use dev-libs/libffi to call native methods
dev-java/jcs:admin - Enable JCS Admin servlets
dev-java/jdbc-jaybird:jni - Build/Install JDBC Type 2 native components
dev-java/jdbc-mysql:c3p0 - Enable c3p0 support
dev-java/jdbc-mysql:log4j - Enable log4 support
dev-java/jdbc-oracle-bin:dms - Enable support for the Oracle Dynamic Monitoring Service
dev-java/jdbc-oracle-bin:ons - Enable support for the Oracle Notification Services (ONS) deamon
dev-java/jdbc-postgresql:java5 - Enable Java 5 specific features
dev-java/jruby:bsf - Enable support for Apache Bean Scripting Framework
dev-java/log4j:javamail - Build the SMTPAppender
dev-java/log4j:jms - Build the JMSAppender
dev-java/log4j:jmx - Build org.apace.log4j.jmx
dev-java/quartz:dbcp - Enable dbcp support
dev-java/quartz:jboss - Enable JBoss support
dev-java/quartz:jmx - Enable jmx support
dev-java/quartz:jta - Enable jta support
dev-java/quartz:servlet-2_3 - Enable servlet-2.3 support
dev-java/quartz:servlet-2_4 - Enable servlet-2.4 support
dev-java/quartz:struts - Enable struts support
dev-java/rxtx:lfd - Installs and uses LockFileServer daemon (lfd)
dev-java/sun-jaxp-bin:dom4j - Enable dom4j
dev-java/sun-jdk:jce - Enable Java Cryptographic Extension Unlimited Strength Policy files
dev-java/tomcat-servlet-api:java5 - Use Java 1.5 source/target for compilation
dev-java/xstream:java5 - Enable Java 5 specific features
dev-lang/erlang:hipe - HIgh Performance Erlang extension
dev-lang/erlang:kpoll - Enable kernel polling support
dev-lang/erlang:smp - Enable support for multiprocessors
dev-lang/gdl:hdf - Adds support for the Hierarchical Data Format
dev-lang/gdl:hdf5 - Adds support for the Hierarchical Data Format v 5
dev-lang/gdl:proj - Adds proj library support (geographic projections)
dev-lang/gforth:force-reg - Enable a possibly unstable GCC flag for possibly large performance gains
dev-lang/ghc:binary - Install the binary version directly, rather than using it to build the source version.
dev-lang/ghc:ghcbootstrap - Internal: Bootstrap GHC from an existing GHC installation.
dev-lang/icon:iplsrc - install the icon programming library source
dev-lang/ocaml:latex - Add ocamldoc support for latex
dev-lang/perl:ithreads - Enable Perl threads, has some compatibility problems
dev-lang/perl:perlsuid - Enable Perl SUID install. Has some risks associated.
dev-lang/php:cgi - Enable CGI SAPI
dev-lang/php:cli - Enable CLI SAPI
dev-lang/php:concurrentmodphp - Make it possible to load both mod_php4 and mod_php5 into the same Apache2 instance (experimental)
dev-lang/php:discard-path - Switch on common security setting for CGI SAPI
dev-lang/php:fastbuild - Build PHP quicker (experimental)
dev-lang/php:fdftk - Add supports for Adobe's FDF toolkit.
dev-lang/php:filter - Add filter extension support
dev-lang/php:force-cgi-redirect - Switch on common security setting for CGI SAPI
dev-lang/php:hash - Enable the hash extension
dev-lang/php:java-external - Use the external java extension rather than the bundled one
dev-lang/php:java-internal - Use the bundled java extension in PHP4
dev-lang/php:json - Enable JSON support
dev-lang/php:ldap-sasl - Add SASL support for the PHP LDAP extension
dev-lang/php:ming - Adds support for creating SWF files using Ming
dev-lang/php:oci8-instant-client - Use dev-db/oracle-instantclient-basic as Oracle provider instead of requiring a full Oracle server install
dev-lang/php:overload - Enable the overload extension
dev-lang/php:pdo - Enable the bundled PDO extensions
dev-lang/php:pdo-external - Use the external pecl-pdo extension rather than the bundled one
dev-lang/php:reflection - Enable the reflection extension (Reflection API)
dev-lang/php:suhosin - Add Suhosin support (patch and extension from http://www.suhosin.org/)
dev-lang/php:xmlreader - Enable XMLReader support
dev-lang/php:xmlwriter - Enable XMLWriter support
dev-lang/php:zip - Enable ZIP file support
dev-lang/php:zip-external - Enable ZIP file support (external PECL extension)
dev-lang/python:nothreads - Disable threads (DON'T USE THIS UNLESS YOU KNOW WHAT YOU'RE DOING)
dev-lang/python:ucs2 - Enable byte size 2 unicode (DON'T USE THIS UNLESS YOU KNOW WHAT YOU'RE DOING)
dev-lang/smarteiffel:tcc - use tcc instead of gcc for build (g++ is still used for c++ code)
dev-lang/spidermonkey:threadsafe - Build a threadsafe version of spidermonkey
dev-lang/ruby:rubytests - Install ruby tests that can only be run after ruby is installed
dev-lang/swig:pike - Enable Pike scripting support
dev-libs/DirectFB-extra:flash - Adds support for creating SWF files using Ming
dev-libs/DirectFB:fusion - add Multi Application support (fusion kernel device)
dev-libs/DirectFB:sysfs - Add support for the sysfs filesystem (requires Linux-2.6+)
dev-libs/DirectFB:v4l2 - Enables video4linux2 support
dev-libs/STLport:boost - Enable the usage of boost
dev-libs/ace:tao - include the ACE ORB (CORBA stuff) (called tao) into the build of ace
dev-libs/ace:ciao -include Component Intergraced Ace ORB into the build of ace
dev-libs/apr:urandom - Use /dev/urandom instead of /dev/random
dev-libs/boost:bcp - Install the bcp tool http://www.boost.org/tools/bcp/bcp.html
dev-libs/boost:bjam - Install the BoostJam tool http://www.boost.org/tools/build/jam_src/index.html
dev-libs/boost:icu - Add unicode support to boost.regex using dev-libs/icu
dev-libs/boost:pyste - Add support for the pyste frontend
dev-libs/boost:threadsonly - Only build multithreaded libs
dev-libs/boost:tools - Build and install the boost tools (bcp,quickbook,inspect,wave)
dev-libs/cyberjack:noudev - disable installation of udev rules
dev-libs/cyberjack:pcsc-lite - enable installation of pcsc-lite driver
dev-libs/cyrus-sasl:authdaemond - Enable Courier-IMAP authdaemond's unix socket support.
dev-libs/cyrus-sasl:ntlm_unsupported_patch - Adds NTLM samba NOT supported patch
dev-libs/cyrus-sasl:sample - Build sample client and server
dev-libs/cyrus-sasl:srp - Enables SRP in cyrus-sasl
dev-libs/cyrus-sasl:urandom - Use /dev/urandom instead of /dev/random
dev-libs/fcgi:html - Adds HTML documentation.
dev-libs/ferrisloki:stlport - Include support for STLport
dev-libs/klibc:n32 - Force klibc to 32bit if on mips64 if not n32 userland.
dev-libs/libgcrypt:idea - Use the patented IDEA algorithm
dev-libs/libjit:interpreter - Enable the libjit interpreter
dev-libs/libjit:long-double - Enable the use of long double for jit_nfloat
dev-libs/libjit:new-reg-alloc - Enable new register allocator
dev-libs/libmix:no-net2 - disable libpcap and libnet support
dev-libs/libprelude:swig - Enable rebuild of swig bindings
dev-libs/libpreludedb:swig - Enable rebuild of swig bindings
dev-libs/libproccpuinfo:sender - Build a utility for sending the author your /proc/cpuinfo file.
dev-libs/libsqlora8:orathreads - specifies use of Oracle threads
dev-libs/libtomcrypt:libtommath - Use the portable math library
dev-libs/libtomcrypt:tomsfastmath - Use the optimized math library
dev-libs/libwbxml:nokia6600 - Add support for Nokia 6600 mobile phone
dev-libs/log4cxx:smtp - offer SMTP support via libsmtp
dev-libs/nss:utils - Install utilities included with the library
dev-libs/opencryptoki:tpmtok - offer support for TPM token
dev-libs/openobex:irda - enable IrDA support
dev-libs/openobex:syslog - enable syslog support
dev-libs/opensc:openct - build using dev-libs/openct compatibility
dev-libs/opensc:pcsc-lite - build with pcsc-lite
dev-libs/pwlib:v4l2 - Enable video4linux2 support
dev-libs/qsa:ide - enable the qsa ide
dev-libs/wx-xmingw:gdb - Enable gdb debugging
dev-libs/wx-xmingw:monolithic - Build a monolithic lib
dev-libs/wx-xmingw:mslu - Enable mslu support
dev-libs/wx-xmingw:shared - Enable shared libs
dev-lisp/abcl-cvs:jpty - Enable PTY support
dev-lisp/abcl-cvs:libabcl - Enable ^C handler (from JNI)
dev-lisp/abcl:clisp - Build Armed Bear Common Lisp using GNU CLISP
dev-lisp/abcl:cmucl - Build Armed Bear Common Lisp using CMU Common Lisp
dev-lisp/abcl:jad - Enable support for disassembling compiled code using JAD
dev-lisp/cl-araneida:standalone - tired of waiting for the lisp team to add this
dev-lisp/cl-tbnl:standalone - use TBNL without a front-end (ie. no Apache dependency)
dev-lisp/clisp:new-clx - Build CLISP with support for the NEW-CLX module which is a C binding to the Xorg libraries
dev-lisp/cmucl:nosource - don't include source code for CMUCL in installation
dev-lisp/ecls:c++ - Build ECL with a C++ compiler
dev-lisp/gcl-cvs:custreloc - build a GCL which uses custom GCL code for linking
dev-lisp/gcl-cvs:dlopen - build a GCL which uses dlopen for linking
dev-lisp/gcl-cvs:gprof - build a GCL with profiling support
dev-lisp/gcl:ansi - build a GCL with ANSI support (else build a traditional CLtL1 image)
dev-lisp/gcl:custreloc - build a GCL which uses custom GCL code for linking
dev-lisp/gcl:dlopen - build a GCL which uses dlopen for linking
dev-lisp/gcl:gprof - build a GCL with profiling support
dev-lisp/sbcl:ldb - include support for the SBCL low level debugger
dev-lisp/sbcl:cobalt - mips only: use mipsel binary instead of mips big endian binary to bootstrap
dev-ml/lablgtk:glade - Enable libglade bindings compilation.
dev-ml/lablgtk:gnomecanvas - Enable libgnomecanvas bindings compilation.
dev-ml/ocamlnet:httpd - Enables nethttpd web server component 
dev-perl/Eidetic:auth - Enables Apache-AuthTicket based cookie authentication
dev-perl/GD:animgif - Enable animated gif support
dev-perl/HTML-Mason:modperl - Enable modperl support
dev-perl/PDL:badval - Enable badval support in PDL
dev-perl/RPC-XML:modperl - Enable modperl support
dev-perl/Template-Toolkit:latex - Enable latex support
dev-php/PEAR-MDB2:oci8-instant-client - Use dev-db/oracle-instantclient-basic as Oracle provider instead of requiring a full Oracle server install
dev-php4/eaccelerator:contentcache - Enable content caching
dev-php4/eaccelerator:disassembler - Enable the eA disassembler
dev-php4/eaccelerator:inode - Use inode-based caching
dev-php5/eaccelerator:contentcache - Enable content caching
dev-php5/eaccelerator:disassembler - Enable the eA disassembler
dev-php5/eaccelerator:inode - Use inode-based caching
dev-php5/pecl-pdo-oci:oci8-instant-client - Use dev-db/oracle-instantclient-basic as Oracle provider instead of requiring a full Oracle server install
dev-php5/pecl-pdo:oci8-instant-client - Use dev-db/oracle-instantclient-basic as Oracle provider instead of requiring a full Oracle server install
dev-php5/php-gtk:extra - Enable GtkExtra support
dev-php5/php-gtk:html - Enable GtkHTML2 support
dev-php5/php-gtk:mozembed - Enable GtkMozembed support
dev-php5/php-gtk:sourceview - Enable GtkSourceView support
dev-php5/php-gtk:libsexy - Enable libsexy support
dev-php5/php-gtk:scintilla - Enable Scintilla support
dev-php5/php-gtk:nolibglade - Disable support for libglade
dev-python/cgkit:3ds - enable support for importing 3D Studio models
dev-python/cgkit:ogre - enable support for Ogre rendering
dev-python/docutils:glep - Install support for GLEPs
dev-python/ipython:gnuplot - enable gnuplot support
dev-python/kaa-metadata:css - Enables ripping/reading of encrypted dvds
dev-python/ldaptor:web - enable the web front end for ldaptor (uses dev-python/nevow)
dev-python/nose:twisted - install nose.twistedtools to integrate tests with twisted
dev-python/paste:flup - enable support for flup (and therefore for various wgsi servers and middleware)
dev-python/paste:openid - enable OpenID support
dev-python/psycopg:mxdatetime - choose MX DateTime support instead of built-in datetime
dev-python/pycairo:numeric - enable Numeric support
dev-python/pyzor:pyzord - enable support for pyzord
dev-python/soya:ode - include support for Open Dynamics Engine
dev-python/twisted:serial - include serial port support
dev-python/visual:numarray - enable support for numarray
dev-python/visual:numeric - enable support for numeric
dev-ruby/nitro:lighttpd - install lighttpd
dev-ruby/nitro:xslt - enable xslt support
dev-ruby/og:kirbybase - enable Kirbybase support
dev-ruby/ruby-sdl:image - enable sdl-image support
dev-ruby/ruby-sdl:mixer - enable sdl-mixer support
dev-ruby/ruby-sdl:sge - enable sdl-sge support
dev-ruby/rubygems:server - rubygems server support
dev-ruby/sqlite3-ruby:swig - Use swig to generate binding
dev-scheme/drscheme:3m - compile drscheme3m binary that uses the 3m GC instead of the Boehm GC
dev-scheme/drscheme:backtrace - support GC backtrace dumps
dev-scheme/drscheme:cgc - compile and install additional executables which use the conservative garbage collector
dev-scheme/drscheme:llvm - add support for compiling to the low-level virtual machine (llvm)
dev-scheme/drscheme:xft - add support for xft
dev-scheme/drscheme:xrender - add support for xrender
dev-scheme/gambit:big-iron - use expensive GCC optimizations and compile syntax-case macro system, try only if you have more than 2GB RAM
dev-scheme/gauche-gl:cg - enable NVidia Cg binding
dev-scheme/gauche-gtk:glgd - enable GL graph draw
dev-scheme/guile:debug-freelist - include garbage collector freelist debugging code
dev-scheme/guile:debug-malloc - include malloc debugging code
dev-scheme/guile:deprecated - enable deprecated features
dev-scheme/guile:discouraged - (implied by deprecated) enable merely discouraged features
dev-scheme/guile:elisp - enable Emacs Lisp support
dev-scheme/guile:networking - include networking interfaces
dev-scheme/guile:regex - include regular expression interfaces
dev-tex/latex-beamer:lyx - Install with LyX layouts
dev-util/anjuta:devhelp - Enable devhelp integration
dev-util/anjuta:glade - Build glade plugin for anjuta
dev-util/anjuta:inherit-graph - Build inheritance graphing plugin for anjuta
dev-util/anjuta:sourceview - Build sourceview editing plugin for anjuta
dev-util/anjuta:subversion - Build subversion plugin for anjuta
dev-util/anjuta:valgrind - Build valgrind plugin for anjuta
dev-util/buildbot:irc - Add support for status delivery through an ircbot.
dev-util/buildbot:mail - Add support for watching a maildir for commits.
dev-util/buildbot:web - Add a web interface ("waterfall" page).
dev-util/catalyst:ccache - Enables ccache support
dev-util/ctags:ada - Enable Ada support
dev-util/codeblocks:contrib - Build additional contrib components
dev-util/cvs:server - Enable server support
dev-util/debootstrap:nodpkg - Don't install dpkg (useful for building a non-debian system)
dev-util/eclipse-sdk:branding - Enable Gentoo branded splash screen
dev-util/eric:idl - Enable omniorb support
dev-util/git:mozsha1 - makes git use an optimized SHA1 routine from Mozilla that should be fast on non-x86 machines
dev-util/git:ppcsha1 - Make use of a bundled routine that is optimized for the PPC arch
dev-util/git:webdav - Adds support for push'ing to HTTP repositories via DAV
dev-util/glade:devhelp - Enable help support through devhelp
dev-util/global:vim - vim funny stuff for global
dev-util/kdevelop:ada - Support for the Ada programming language.
dev-util/kdevelop:clearcase - Support for the ClearCase version control system.
dev-util/kdevelop:cvs - Support for CVS via kde-base/cervisia.
dev-util/kdevelop:haskell - Support for the Haskell programming language.
dev-util/kdevelop:pascal - Support for the Pascal programming language.
dev-util/kdevelop:perforce - Support for the Perforce version control system.
dev-util/kdevelop:sql - Support for the Structured Query Language (SQL).
dev-util/kdevelop:subversion - Support for the Subversion version control system.
dev-util/mercurial:zsh-completion - Install zsh command completion for hg
dev-util/monodevelop:aspnet - Enable ASP.NET support
dev-util/monodevelop:aspnetedit - Enable ASP.NET visual designer support
dev-util/monodevelop:boo - Enable support for the boo programming language
dev-util/monodevelop:subversion - Enable subversion support
dev-util/netbeans:c++ - Adds Netbeans C/C++ Pack
dev-util/nsis:config-log - Enable the logging facility (useful in debugging installers)
dev-util/pbuilder:uml - Enable pbuilder user mode linux support
dev-util/strace:aio - Enable libaio support
dev-util/subversion:extras - Install extras scripts (examples, tools, hooks)
dev-util/subversion:nowebdav - Disables WebDAV support via neon library
dev-util/svk:pager - Enable perl pager selection support
dev-util/svk:patch - Enable patch creation, import support
dev-util/svk:svn-mirror - Enable SVN-Mirror support
games-action/d1x-rebirth:awe32 - Enable AWE32 support
games-action/d1x-rebirth:demo - Use the demo data instead of the full game
games-action/d1x-rebirth:mixer - Enable mixer support
games-action/d1x-rebirth:mpu401 - Enable MPU401 music support
games-action/d2x-rebirth:awe32 - Enable AWE32 support
games-action/d2x-rebirth:mpu401 - Enable MPU401 music support
games-action/xshipwars:yiff - Add support for the YIFF sound server
games-arcade/bomns:editor - enables building the level editor
games-arcade/lbreakout2:themes - Install additional themes
games-arcade/stepmania:force-oss - force using OSS
games-arcade/triplexinvaders:psyco - psyco python accelerator
games-arcade/ultrastar-ng:novideo - Disable smpeg video support
games-board/chessdb:tb4 - Install 4 pieces table bases
games-board/crafty:no-opts - Don't try to enable crazy CFLAG options
games-board/freedoko:altenburgcards - Use the Altenburg card set
games-board/freedoko:kdecards - Use the KDE card set
games-board/freedoko:net - Enable network game support
games-board/freedoko:pysolcards - Use the PySol card set
games-board/freedoko:xskatcards - Use the XSkat card set
games-board/grhino:gtp - Install the GTP (Go/Game Text Protocol) frontend
games-board/pysol:extra-cardsets - Install extra cardsets
games-board/xboard:zippy - Enable experimental zippy client
games-emulation/generator:sdlaudio - Enable SDL Audio
games-emulation/mupen64-glN64:asm - Enable use of asm routines to improve performance
games-emulation/xmame:net - Add network support
games-emulation/xmess:net - Add network support
games-emulation/zsnes:custom-cflags - Enables custom cflags (not supported)
games-engines/exult:timidity - Add sound support (timidity)
games-engines/scummvm:fluidsynth - compile with support for fluidsynth
games-fps/alephone:smpeg - Enables use of smpeg 
games-fps/darkplaces:cdsound - Enables using CD audio in the engine
games-fps/darkplaces:demo - Uses the demo data from quake1 (quake1-demodata)
games-fps/darkplaces:dpmod - Sets up the darkplaces mod from icculus
games-fps/darkplaces:lights - Install and setup the updated light maps
games-fps/darkplaces:textures - Install and setup the updated textures
games-fps/doom-data:doomsday - Add wrapper to run it within doomsday
games-fps/doom3:roe - Adds support for the Resurrection of Evil expansion
games-fps/duke3d:demo - Install the demo files
games-fps/freedoom:doomsday - Add wrapper to run it within doomsday
games-fps/nexuiz:maps - Install the community map pack
games-fps/quake2-icculus:demo - Install the demo files (quake2-demodata) and configure for use
games-fps/quake2-icculus:noqmax - Do not build the pretty version (quake max)
games-fps/quake2-icculus:qmax - Build the pretty version (quake max)
games-fps/quake2-icculus:rogue - Build support for the 'Ground Zero' Mission Pack (rogue)
games-fps/quake2-icculus:xatrix - Build support for the 'The Reckoning' Mission Pack (xatrix)
games-fps/quake3-bin:teamarena - Adds support for Team Arena expansion pack
games-fps/quake3:teamarena - Adds support for Team Arena expansion pack
games-fps/qudos:demo - Install the demo files (quake2-demodata) and configure for use
games-fps/qudos:mods - Build support for the quake2 mission packs
games-fps/qudos:qmax - Build the pretty version (quake max)
games-fps/qudos:textures - Install the enhanced textures (quake2-textures)
games-fps/rott:demo - Install the shareware version
games-fps/unreal-tournament-goty:S3TC - Add the extra fancy textures to UT ... only works on certain cards (nvidia/ati/s3)
games-fps/warsow:irc - Enable IRC support
games-kids/gcompris:gnet - will let GCompris fetch content from a web server
games-mud/mmucl:mccp - adds support for the Mud Client Compression Protocol
games-roguelike/scourge:editor - Install Scourge Data Editor (scourge-tools)
games-rpg/eternal-lands-data:music - Install optional music files (extra 30 meg)
games-rpg/galaxymage:psyco - psyco python accelerator
games-rpg/nwn-cep:hou - Adds support for the Hordes of the Underdark expansion pack
games-rpg/nwn-cep:sou - Adds support for the Shadows of Undrentide expension pack
games-rpg/nwn-data:hou - Install the Hordes of the Underdark expansion pack
games-rpg/nwn-data:nowin - For those people who cant grab the 1.2 gigs of data files from a windows partition
games-rpg/nwn-data:sou - Installs the Shadows of Undrentide expension pack
games-rpg/nwn:hou - Install the Hordes of the Underdark expansion pack
games-rpg/nwn:sou - Installs the Shadows of Undrentide expension pack
games-simulation/openttd:scenarios - Install additional contributed scenarios
games-simulation/openttd:timidity - Add sound support (timidity)
games-sports/xmoto:editor - Depend on inkscape, scripts to convert svg to level (svg2lvl)
games-strategy/dark-oberon:fmod - Add sound support (fmod)
games-strategy/freeciv:auth - Add authentication capability
games-strategy/freelords:editor - Installs optional map editor
games-strategy/heroes3:maps - Installs optional map data
games-strategy/heroes3:music - Installs optional music data
games-strategy/heroes3:sounds - Installs optional sound data
games-strategy/ufo-ai:master - Enable building master server
games-strategy/ufo-ai:paranoid - Enable paranoid debugging code
games-strategy/uqm:music - download and install music files (large)
games-strategy/uqm:remix - download and install music remix files (large)
games-strategy/uqm:voice - download and install voice files (large)
games-strategy/wesnoth:editor - Enable compilation of map editor
games-strategy/wesnoth:lite - Lite install
games-strategy/wesnoth:server - Enable compilation of server
games-strategy/wesnoth:tools - Enable compilation of translation tools
games-strategy/x2:bonusscripts - Add bonus scripts
games-strategy/x2:dynamic - Use dynamic binaries instead of static
games-strategy/x2:german - Enable German as default language
games-strategy/x2:langpacks - Install additional language packs
games-strategy/x2:modkit - Install the modkit
gnome-base/gdm:branding - Enable a custom gentoo branded artwork
gnome-base/gnome-session:branding - Enable a custom gentoo branded splashscreen
gnome-base/nautilus:beagle - Enable support for beagle searching
gnome-base/nautilus:tracker - Enable support for tracker searching
gnome-extra/evolution-data-server:keyring - Use gnome-keyring for password storage
gnome-extra/gnome-games:artworkextra - Add extra Artwork to gnome-games
gnome-extra/libgda:mdb - Enable Microsoft Access DB support for GnomeDB.
gnome-extra/libgda:xbase - Enable support for xbase databases (dBase, FoxPro, etc)
gnome-extra/nautilus-sendto:gaim - Build a gaim plugin for nautilus-sendto
gnome-extra/nautilus-sendto:gajim - Enable support for gajim client
gnome-extra/nautilus-sendto:pidgin - Enable support for pidgin
gnome-extra/nautilus-sendto:sylpheed - Enable support for sylpheed mail client
gnome-extra/nautilus-sendto:thunderbird - Enable support for thunderbird
gnome-extra/sensors-applet:hddtemp - Enable support the hddtemp daemon
gnome-extra/sensors-applet:nvidia - Enable support for nvidia sensors
gnome-extra/yelp:beagle - Enable beagle support
gnome-extra/zim:trayicon - Enable support for trayicon
gnustep-apps/cynthiune:modplug - Build with modplug support
gnustep-apps/cynthiune:timidity - Build with Timidity++ (MIDI sequencer) support
gnustep-apps/gnumail:emoticon - Enable extra Emoticon Bundle to see smiley's in e-mail messages.
gnustep-base/gnustep-back-art:xim - Enable X11 XiM input method
gnustep-base/gnustep-back-cairo:glitz - Build with glitz support
gnustep-base/gnustep-back-cairo:xim - Enable X11 XiM input method
gnustep-base/gnustep-back-xlib:xim - Enable X11 XiM input method
gnustep-base/gnustep-base:gcc-libffi - Offers a migration path away from the ill fated dev-libs/libffi; gcc-3.* will generally have to be compiled with 'gcj' on, >=gcc-3.4.3-r1 can be used with only 'objc' turned on (this will reduce compile time).
gnustep-base/gnustep-gui:gsnd - Enable GNUstep sound server
gnustep-base/gnustep-make:layout-from-conf-file - Layout GNUstep according to /etc/conf.d/gnustep.env; GNUSTEP_SYSTEM_ROOT, GNUSTEP_LOCAL_ROOT, GNUSTEP_NETWORK_ROOT, and GNUSTEP_USER_ROOT (use '~' or '~/whatever' -- SURROUNDED BY SINGLE QUOTES -- for the user root); the only required entry is GNUSTEP_SYSTEM_ROOT; GNUSTEP_SYSTEM_ROOT must end with "System".
gnustep-base/gnustep-make:layout-osx-like - Layout GNUstep FHS like OSX's (violates Linux FHS, but arguably more NeXT-like); User, Local, Network, and System are set to (in order): "~", "/", "/Network", "/System"
gnustep-base/gnustep-make:non-flattened - do not flatten launch and library paths for GNUstep packages allowing executable within a .app to be launched based on processor type
kde-base/arts:artswrappersuid - Set artswrapper suid for realtime playing, which is a security hazard.
kde-base/juk:akode - Support for the aKode audio-decoding frame-work.
kde-base/kaddressbook:gnokii - Address synchronization with mobile phones via Gnokii.
kde-base/kbugbuster:kcal - Support for kcal (calendar) format.
kde-base/kcontrol:logitech-mouse - Build the Control Center module to configure logitech mice.
kde-base/kdebase:branding - Gentoo specific web shortcuts.
kde-base/kdebase:logitech-mouse - Build the Control Center module to configure logitech mice
kde-base/kdebase:zeroconf - Support for DNS Service Discovery (DNS-SD).
kde-base/kdeedu:kig-scripting - Support Python scripting in kig.
kde-base/kdegraphics-meta:povray - Install KPovModeler, which needs POV-Ray.
kde-base/kdegraphics:povray - Install KPovModeler, which needs POV-Ray.
kde-base/kdelibs:branding - Gentoo branded KHTML user agent.
kde-base/kdelibs:legacyssl - Support for some deprecated ciphers. Don't use this flag unless you really need it.
kde-base/kdelibs:utempter - Records everytime a user logins in. Useful on multi-user systems.
kde-base/kdelibs:zeroconf - Support for DNS Service Discovery (DNS-SD).
kde-base/kdemultimedia:akode - Support for the aKode audio-decoding frame-work.
kde-base/kdenetwork:jingle - Enables voice calls for jabber
kde-base/kdenetwork:sametime - Support for the Sametime protocol for instant messaging.
kde-base/kdepim:gnokii - Address synchronization with mobile phones via Gnokii.
kde-base/kdesdk-meta:subversion - Support for the subversion ioslave.
kde-base/kdesdk:subversion - Support for the subversion ioslave.
kde-base/kdeutils:pbbuttonsd - Support for the Apple PMU daemon pbbuttonsd.
kde-base/kig:kig-scripting - Support Python scripting.
kde-base/kmilo:pbbuttonsd - Support for the Apple PMU daemon pbbuttonsd.
kde-base/konqueror:branding - Gentoo specific web shortcuts.
kde-base/kopete:addbookmarks - Builds Add Bookmarks plugin
kde-base/kopete:alias - Builds Alias plugin
kde-base/kopete:autoreplace - Builds Auto-Replace plugin
kde-base/kopete:connectionstatus - Builds Connection Status plugin
kde-base/kopete:contactnotes - Builds Contact Notes plugin
kde-base/kopete:gadu - Builds GaduGadu protocol handler
kde-base/kopete:groupwise - Builds Novell GroupWise protocol handler
kde-base/kopete:highlight - Builds Highlight plugin
kde-base/kopete:history - Builds history plugin
kde-base/kopete:irc - Builds IRC protocol handler
kde-base/kopete:jingle - Enables voice calls for jabber
kde-base/kopete:latex - Builds LaTeX plugin
kde-base/kopete:netmeeting - Builds netmeeting plugin (require gnomemeeting)
kde-base/kopete:nowlistening - Builds Now Listening... plugin
kde-base/kopete:sametime - Enables support for the Sametime protocol for instant messaging
kde-base/kopete:sms - Builds SMS protocol handler
kde-base/kopete:statistics - Builds statistics plugin
kde-base/kopete:texteffect - Builds Text Effect plugin
kde-base/kopete:translator - Builds Translator plugin
kde-base/kopete:webpresence - Builds Web Presence plugin
kde-base/kopete:winpopup - Builds WinPopUp protocol handler
kde-base/ksysguard:zeroconf - Support for DNS Service Discovery (DNS-SD).
kde-base/kttsd:akode - Support for the aKode audio-decoding frame-work.
kde-misc/knetworkmanager:cisco - Adds support for the Cisco VPN client (vpnc)
kde-misc/knetworkmanager:dialup - Enables Dialup (PPP) support
kde-misc/knetworkmanager:openvpn - Adds support for the OpenVPN client
kde-misc/knetworkmanager:pptp - Adds support for the PPTP (PPP) VPN client
kde-misc/ksensors:hddtemp - Enable monitoring of disk temperatures (app-admin/hddtemp)
kde-misc/ksensors:ibmacpi - Enable monitoring of ACPI sensor data on IBM Thinkpad notebooks.
mail-client/balsa:gtkspell - Use gtkspell for dictionary support
mail-client/claws-mail:bogofilter - Build bogofilter plugin
mail-client/claws-mail:dillo - Enables support for inline http email viewing with a plugin (which depends on the dillo browser)
mail-client/claws-mail:spamassassin - Build spamassassin plugin
mail-client/evolution:bogofilter - Use bogofilter instead of spamassassin
mail-client/mail-notification:gmail - Enable Gmail mailbox checking
mail-client/mail-notification:pop - Enable support for pop
mail-client/mail-notification:sylpheed - Enable support for MH mailboxes used by sylpheed
mail-client/mozilla-thunderbird:mozdom - Enable Mozilla's DOM inspector
mail-client/mozilla-thunderbird:moznopango - Disable pango during runtime
mail-client/mozilla-thunderbird:replytolist - Enable reply-to-list plugin
mail-client/mutt:buffysize - Enables buffysize workaround, see bug 72422
mail-client/mutt:gpgme - Enable support for gpgme
mail-client/mutt:pop - Enable support for pop
mail-client/mutt:sidebar - Use the vanilla tree + sidebar patch
mail-client/mutt:smime - Enable support for smime
mail-client/mutt:smtp - Enable support for smtp
mail-client/muttng:buffysize - Enables buffysize workaround, see bug 72422
mail-client/muttng:gpgme - Enable support for gpgme
mail-client/muttng:pop - Enable support for pop
mail-client/muttng:smime - Enable support for smime
mail-client/muttng:smtp - Enable support for smtp
mail-client/nail:net - Enable network support (thus enabling POP, IMAP and SMTP)
mail-client/pine:largeterminal - Add support for large terminals by doubling the size of pine's internal display buffer
mail-client/pine:passfile - Adds support for caching IMAP passwords into a file between sessions
mail-client/squirrelmail:filter - Enable amavisd-new filtering
mail-filter/amavisd-new:courier - Add support for usage with courierfilter
mail-filter/amavisd-new:qmail - Add support for qmail
mail-filter/ask:procmail - Adds support for procmail
mail-filter/assp:spf - Adds support for Sender Policy Framework
mail-filter/assp:srs - Adds support for Sender Rewriting Scheme
mail-filter/bsfilter:mecab - Adds support for mecab
mail-filter/clamassassin:clamd - Use the ClamAV daemon for virus checking.
mail-filter/clamassassin:subject-rewrite - Adds support for subject rewriting.
mail-filter/dcc:rrdtool - Enable rrdtool interface scripts
mail-filter/dspam:daemon - Enable support for DSPAM to run in --daemon mode
mail-filter/dspam:large-domain - Builds for large domain rather than for domain scale
mail-filter/dspam:logrotate - Install support files for logrotate
mail-filter/dspam:user-homedirs - Build with user homedir support
mail-filter/dspam:virtual-users - Build with virtual-users support
mail-filter/maildrop:authlib - Add courier-authlib suport
mail-filter/qmail-scanner:spamassassin - Build faster spamassassin checks into qmail-scanner
mail-filter/simscan:attachment - Enable attachment scanning
mail-filter/simscan:dropmsg - Drop messages in case of virus/spam
mail-filter/simscan:passthru - Passthru messages in case of virus/spam
mail-filter/simscan:per-domain - Enable support for per-domain settings
mail-filter/simscan:quarantine - Enable quarantine support
mail-filter/simscan:regex - Enable regular expression matching
mail-filter/simscan:received - Add Received: line to mail headers
mail-filter/simscan:spamassassin - Use spamassassin for spam checking
mail-filter/spamassassin-fuzzyocr:amavis - Enable support for amavis
mail-filter/spamassassin-fuzzyocr:gocr - Enable support for the gocr OCR engine
mail-filter/spamassassin-fuzzyocr:logrotate - Install support files for logrotate
mail-filter/spamassassin-fuzzyocr:ocrad - Enable support for the ocrad OCR engine
mail-filter/spamassassin-fuzzyocr:tesseract - Enable support for the tesseract OCR engine
mail-filter/spamassassin:qmail - Build qmail functionality and docs
mail-filter/spamassassin:tools - Enables tools for spamassassin
mail-mta/courier:fax - Enables fax support in the courier mail server
mail-mta/courier:norewrite - Prevents courier mail server from mangling virtual user addresses when sending
mail-mta/exim:dnsdb - Adds support for a DNS search for a record whose domain name is the supplied query
mail-mta/exim:domainkeys - Adds support for Yahoo!'s Domainkey sender verification system
mail-mta/exim:dovecot-sasl - Adds support for Dovecot's authentication
mail-mta/exim:exiscan - Patch providing support for content scanning backward-compatibility
mail-mta/exim:exiscan-acl - Patch providing support for content scanning
mail-mta/exim:lmtp - Adds support for lmtp
mail-mta/exim:mbx - Adds support for UW's mbx format
mail-mta/exim:spf - Adds support for Sender Policy Framework
mail-mta/exim:srs - Adds support for Sender Rewriting Scheme
mail-mta/exim:syslog - defines syslog as the default log path if none is specified in the conf file.
mail-mta/netqmail:gencertdaily - Generate SSL certificates daily instead of hourly
mail-mta/netqmail:highvolume - Prepare netqmail for high volume servers
mail-mta/netqmail:noauthcram - If you do NOT want AUTHCRAM to be available
mail-mta/netqmail:qmail-spp - Add support for the qmail SMTP plugin patch
mail-mta/postfix:dovecot-sasl - Enable Dovecot protocol version 1 (server only) SASL implementation
mail-mta/postfix:vda - Adds support for virtual delivery agent quota enforcing
mail-mta/qmail-ldap:controldb - Add support for the QmailLDAP/Control patch (stores control files in ldap)
mail-mta/qmail-ldap:gencertdaily - Generate SSL certificates daily instead of hourly
mail-mta/qmail-ldap:highvolume - Prepare qmail for high volume servers
mail-mta/qmail-ldap:cluster - Enable this if you want to have cluster support in qmail-ldap
mail-mta/qmail-ldap:qmail-spp - Add support for the qmail SMTP plugin patch
mail-mta/qmail-ldap:rfc822 - Add support for RFC822 compliant mail attributes
mail-mta/qmail-ldap:rfc2307 - Add support for RFC2307 compliant uid/gid attributes
mail-mta/ssmtp:md5sum - Enables MD5 summing for ssmtp
media-fonts/intlfonts:bdf - Installs BDF fonts in addition to PCF
media-gfx/asymptote:boehm-gc - Enables using the Boehm-Demers-Weiser conservative garbage collector
media-gfx/autotrace:flash - Adds support for creating SWF files using Ming
media-gfx/blender:blender-game - Adds game engine support to blender
media-gfx/blender:verse - Adds verse clustering features to blender
media-gfx/comix:rar - Pulls app-arch/unrar for rar file support
media-gfx/dcraw:gimp - Builds rawphoto plugin for the GIMP
media-gfx/digikam:nfs - Create sqlite db within ~/.kde, instead in the albums base directory.
media-gfx/gimp:gimpprint - Enable gimp-print printing support
media-gfx/gimp:smp - Enable support for multiprocessors
media-gfx/gimp-print:gimp - Build a plugin for the GIMP
media-gfx/graphicsmagick:depth16 - use 16-bit color depth as default
media-gfx/graphicsmagick:depth32 - use 32-bit color depth as default
media-gfx/graphicsmagick:gs - enable ghostscript support
media-gfx/graphicsmagick:lzw - enable LZW support
media-gfx/graphviz:pango - Enables the rendering of the graphs using pango & cairo (with antialiasing support)
media-gfx/gthumb:iptc - Add support for IPTC metadata
media-gfx/gthumb:raw - Add support for raw image formats 
media-gfx/gtkam:gimp - GIMP plugin from gtkam
media-gfx/gwenview:kipi - Support for the KDE Image Plugin Interface.
media-gfx/hugin:enblend - Pull media-gfx/enblend as a dependency
media-gfx/hugin:sift - Pull media-gfx/autopano-sift as a dependency
media-gfx/imagemagick:fpx - enable libfpx support
media-gfx/imagemagick:hdri - Enables High Dynamic Range Images formats
media-gfx/imagemagick:gs - enable ghostscript support
media-gfx/imagemagick:q32 - Set quantum depth to 32
media-gfx/imagemagick:q8 - Set quantum depth to 8
media-gfx/inkscape:boost - use external boost
media-gfx/inkscape:dia - Pull in app-office/dia for dia import extension
media-gfx/inkscape:inkjar - enables inkjar support
media-gfx/inkscape:plugin - enables extra plugins
media-gfx/inkscape:postscript - Pull in dependencies needed for the postscript import extension
media-gfx/iscan:gimp - Build a plugin for the GIMP
media-gfx/k3d:plib - build plib-based import/export library
media-gfx/maya:bundled-libs - Use the bundled versions of libs rather than system ones (libstdc++, libgcc_s, libqt, and libXm)
media-gfx/maya:maya-shaderlibrary - Install the maya shader library
media-gfx/pstoedit:emf - enables media-libs/libemf support
media-gfx/sane-frontends:gimp - Build a plugin for the GIMP
media-gfx/showimg:kipi - Support for the KDE Image Plugin Interface.
media-gfx/ufraw:gimp - Build a plugin for the GIMP
media-gfx/xsane:gimp - Build a plugin for the GIMP
media-libs/a52dec:djbfft - Prefer D.J. Bernstein's library for fourier transforms
media-libs/allegro:vga - Enables the VGA graphics driver
media-libs/alsa-lib:alisp - Enable support for ALISP (ALSA LISP) interpreter for advanced features.
media-libs/alsa-lib:midi - Enables MIDI output support (both Hardware and Software)
media-libs/cal3d:16bit-indices - Enables use of 16bit indices
media-libs/coin:fontconfig - Support for managing custom fonts via fontconfig.
media-libs/devil:allegro - Add support for Allegro
media-libs/farsight:jingle - Enables voice calls for jabber
media-libs/gd:fontconfig - Support for managing custom fonts via fontconfig.
media-libs/giflib:rle - Build converters for RLE format (utah raster toolkit)
media-libs/glide-v3:voodoo1 - Support 3DFX Voodoo1 video cards
media-libs/glide-v3:voodoo2 - Support 3DFX Voodoo2 video cards
media-libs/glide-v3:voodoo5 - Support 3DFX Voodoo4 and Voodoo5 video cards
media-libs/libggi:vis - Enables sparc vis support for libggi
media-libs/libifp:module - Build kernel module for non-root usage
media-libs/libkarma:mono - Build with mono support
media-libs/libquicktime:lame - Support LAME mp3 encoding
media-libs/libsdl:noaudio - Allow users to disable audio support completely (at their own risk)
media-libs/libsdl:noflagstrip - Allow users to use any CFLAGS they like completely (at their own risk)
media-libs/libsdl:nojoystick - Allow users to disable joystick support completely (at their own risk)
media-libs/libsdl:novideo - Allow users to disable video support completely (at their own risk)
media-libs/libvorbis:aotuv - Allow users to enable aoTuV encoder enhancements
media-libs/mesa:xcb - Support the X C-language Binding, a replacement for Xlib
media-libs/mlt:lame - Support LAME mp3 encoding
media-libs/netpbm:rle - Build converters for the RLE format (utah raster toolkit)
media-libs/panda3d:fmod - Enables support for using mod files for audio support
media-libs/panda3d:nspr - Enables support for the Netscape Portable Runtime, used in network interface functionality (ie. multiplayer online game networking).
media-libs/ploticus:cpulimit - Limit cpu usage when generating graphics
media-libs/ploticus:flash - Adds support for creating SWF files using Ming
media-libs/ploticus:svgz - Compressed svg graphics support
media-libs/sdif:ftruncate - Enables usage of ftruncate v. truncate
media-libs/sdl-mixer:timidity - Add support for timidity
media-libs/sdl-sound:physfs - Enable physfs support
media-libs/sge:image - enable sdl-image support
media-libs/speex:vorbis-psy - Enable Vorbis-style psychoacoustics
media-libs/speex:wideband - Enable Wideband codec
media-libs/svgalib:no-helper - Do not build the helper kernel module
media-libs/urt:gs - Add support for postscript
media-libs/win32codecs:real - Installs the real video codecs
media-libs/x264-svn:mp4 - Enables mp4 encoding support
media-libs/xine-lib:dxr3 - Support for DXR3 mpeg accelleration cards
media-libs/xine-lib:modplug - Build with modplug support
media-libs/xine-lib:real - Adds real video support
media-libs/xine-lib:vidix - Support for vidix video output
media-libs/xine-lib:wavpack - Build with WavPack support
media-libs/xine-lib:xcb - Support the X C-language Binding, a replacement for Xlib
media-libs/xine-lib:xvmc - Support for XVideo Motion Compensation (accelerated mpeg playback)
media-plugins/audacious-plugins-ugly:cube - Build with CUBE input plugin (supports formats such as ADX)
media-plugins/audacious-plugins-ugly:iris - Build with Iris 3D visual plugin
media-plugins/audacious-plugins:adplug - Build with AdPlug (Adlib sound card emulation) support
media-plugins/audacious-plugins:chardet - Try to handle non-UTF8 chinese/japanese/korean ID3 tags
media-plugins/audacious-plugins:modplug - Build with modplug support
media-plugins/audacious-plugins:sid - Build with SID (Commodore 64 Audio) support
media-plugins/audacious-plugins:timidity - Build with Timidity++ (MIDI sequencer) support
media-plugins/audacious-plugins:tta - Build with TTA (True-Audio lossless) support
media-plugins/audacious-plugins:wavpack - Build with WavPack support
media-plugins/audacious-plugins:wma - Build with WMA (Windows Media Audio) support
media-plugins/gst-plugins-farsight:gsm - Support for the gsm lossy speech compression library
media-plugins/gst-plugins-farsight:jingle - Enables voice calls for jabber
media-plugins/gst-plugins-farsight:jrtplib - Support for the Real-time Transport Protocol (RTP) library
media-plugins/mythdvd:transcode - Enable DVD ripping and transcoding
media-plugins/mythmusic:libvisual - Enables libvisual support for effects
media-plugins/mythphone:festival - Enable festival support
media-plugins/vdr-burn:projectx - Enables support fur projectx
media-plugins/vdr-dvdconvert:projectx - Enables support for projectx 
media-plugins/vdr-pvr350:yaepg - Enables full support for the ouput format of vdr-yaepg
media-plugins/vdr-softdevice:mmxext - enables mmx2 support
media-plugins/vdr-text2skin:direct_blit - not buffer picture, faster, but only for modified skins
media-plugins/vdr-weatherng:dxr3 - enables lower osd color deep for dxr3 cards
media-sound/abcde:id3 - Support ID3, ID3v2 tagging of audio files
media-sound/abcde:lame - Support LAME mp3 encoding
media-sound/abcde:replaygain - Support for Replay Gain metadata, for relative volume adjustment
media-sound/alsa-driver:midi - Build the sequencer (midi) modules
media-sound/alsa-tools:midi - Build the sequencer (midi) utilities
media-sound/alsa-utils:midi - Build the sequencer (midi) utilities
media-sound/amarok:daap - Enable support for DAAP Music Sharing
media-sound/amarok:ifp - Enable support for iRiver devices access through libifp
media-sound/amarok:mp4 - Enable write support for tags in MP4 files (M4A). The resulting Amarok copy is not redistributable.
media-sound/amarok:mtp - Enable support for libMTP (Plays4Sure) devices access through libmtp
media-sound/amarok:njb - Enable support for NJB (Creative) devices access through libnjb
media-sound/amarok:noamazon - Disable support for downloading covers from amazon.com
media-sound/amarok:real - Build with real/helix player support
media-sound/amarok:visualization - Support visualization plugins through media-libs/libvisual
media-sound/audacious:chardet - Try to handle non-UTF8 chinese/japanese/korean ID3 tags
media-sound/audacious:modplug - Build with modplug support
media-sound/audacious:sid - Build with SID (Commodore 64 Audio) support
media-sound/audacious:timidity - Build with Timidity++ (MIDI sequencer) support
media-sound/audacious:wma - Build with WMA (Windows Media Audio) support
media-sound/banshee:boo - Use external Boo instead of the bundled one
media-sound/banshee:daap - Build with Daap support
media-sound/banshee:njb - Build with njb audio player support
media-sound/bmpx:modplug - Build with modplug support
media-sound/bmpx:networkmanager - Enable networkmanager support
media-sound/bmpx:ofa - Build with ofa/PUID checking support for MusicBrainz metadata
media-sound/bmpx:p2p - Enable support for downloading songs from the SoulSeek p2p network with museekd/mooseekd
media-sound/bmpx:sid - Build with SID (Commodore 64 Audio) support
media-sound/cmus:modplug - Build with modplug support
media-sound/cmus:mp4 - enable mp4 decoding
media-sound/cmus:pidgin - install support script for net-im/pidgin
media-sound/cmus:wavpack - add support for wavpack
media-sound/cmus:wma - add support for Windows Media Audio
media-sound/cmus:zsh-completion - enable zsh completion support
media-sound/darkice:twolame - Build with twolame support
media-sound/dir2ogg:wma - Add support for wma files through mplayer
media-sound/easytag:wavpack - Add support for wavpack
media-sound/exaile:equalizer - Enable equalizer support
media-sound/exaile:libsexy - Enable libsexy support
media-sound/ezstream:taglib - Enable tagging support with taglib
media-sound/freewheeling:fluidsynth - compile with support for fluidsynth
media-sound/gnusound:cpudetection - Enables runtime cpu detection
media-sound/gnusound:lame - Enable lame support
media-sound/herrie:http - Enable http streaming
media-sound/herrie:modplug - Build with modplug support
media-sound/herrie:xspf - Enable support for reading and saving XSPF playlists
media-sound/jack-audio-connection-kit:coreaudio - Build the CoreAudio driver on Mac OS X systems
media-sound/jack-audio-connection-kit:cpudetection - Enables runtime cpudetection
media-sound/jack-audio-connection-kit:jack-tmpfs - Compile in a tmpf path
media-sound/jack-audio-connection-kit:netjack - Build with support for Realtime Audio Transport over generic IP
media-sound/kid3:taglib - Enable tagging support with taglib
media-sound/lame:mp3rtp - Build the mp3-to-RTP streaming utility. **UNSUPPORTED**
media-sound/lastfm-ripper:amazon - Enable advanced tagging using amazon webservices
media-sound/lastfm-ripper:tagwriting - Enable MP3 tagging
media-sound/lilypond:vim - Enable installation of lilypond vim plugins
media-sound/listen:libsexy - Enable libsexy support
media-sound/moc:modplug - Add support for modplug
media-sound/moc:sid - Build with SID (Commodore 64 Audio) support
media-sound/moc:timidity - Add support for timidity
media-sound/moc:wavpack - Add support for wavpack
media-sound/mp3blaster:sid - Build with SID (Commodore 64 Audio) support
media-sound/mpd:icecast - Enable support for Icecast2
media-sound/mpfc:cdaudio - Enable cd audio playback support
media-sound/mpfc:wav - Enable wav audio codec support
media-sound/mpg123:3dnowext - Enable 3dnowext cpu instructions
media-sound/mt-daapd:upnp - Enables support for Intel UPnP stack.
media-sound/murmur:pch - Enable precompiled header support for faster compilation times (gcc >3.4 only)
media-sound/musepack-tools:16bit - Higher quality sound output using dithering and noise-shaping
media-sound/museseq:fluidsynth - compile with support for fluidsynth
media-sound/ncmpc:clock-screen - Enable clock screen
media-sound/ncmpc:key-screen - Enable key editor screen
media-sound/ncmpc:mouse - Enable curses getmouse support
media-sound/ncmpc:raw-mode - raw terminal mode
media-sound/ncmpc:search-screen - Enable search screen (EXPERIMENTAL)
media-sound/noteedit:kmid - Use KDE's kmid to play sound
media-sound/noteedit:tse3 - Use tse3 library to play/export sound
media-sound/picard:cdaudio - Enable support for CD Index Lookups.
media-sound/podcatcher:bittorrent - Enable support for bittorrent downloads
media-sound/prokyon3:taglib - Enable tagging support with taglib
media-sound/quodlibet:mmkeys - Enable support for special keys on multimedia keyboards
media-sound/quodlibet:trayicon - Enable support for trayicon
media-sound/radiomixer:hwmixer - Use hardware mixer instead of internal mixer routines
media-sound/radiomixer:songdb - Enable usage of SongDB backend
media-sound/rezound:16bittmp - Use 16bit temporary files (default 32bit float), usefull for slower computers
media-sound/rezound:soundtouch - compile with support for soundtouch
media-sound/rhythmbox:daap - support for daap
media-sound/rhythmbox:keyring - gnome-keyring support for daap share passwords
media-sound/rhythmbox:tagwriting - support for tag writing in certain audio files
media-sound/rosegarden:dssi - Enable support for DSSI Soft Synth Interface
media-sound/shntool:wavpack - Add support for wavpack
media-sound/slimserver:alac - Enable support for alac
media-sound/sonata:lyrics - Support for lyrics fetching
media-sound/sonata:taglib - Enable tagging support with taglib
media-sound/transkode:amarok - Build Amarok script
media-sound/transkode:wavpack - Add support for wavpack decoding/encoding
media-sound/traverso:lv2 - Add support for Ladspa V2
media-tv/freevo:mixer - Enable support for adjusting volume via media-sound/aumix
media-tv/freevo:tv - Enable support for the tv guide plugin
media-tv/gentoo-vdr-scripts:nvram - Add support for using nvram-wakeup to set wakeup time in bios
media-tv/kdetv:zvbi - Enable VBI Decoding Library for Zapping
media-tv/mythtv:autostart - Controls whether settings are installed for autostarting MythFrontend on boot
media-tv/mythtv:backendonly - Builds only the backend component rather then the whole suite
media-tv/mythtv:crciprec - Enable support for Network Recorder
media-tv/mythtv:dbox2 - Enable support for Nokia DBOX2 DVB boxes
media-tv/mythtv:directv - Install DirecTV channel changer script
media-tv/mythtv:freebox - Enable support for Freebox
media-tv/mythtv:frontendonly - Only builds the Frontend component rather then the whole suite
media-tv/mythtv:hdhomerun - Enable support for HDHomeRun boxes
media-tv/mythtv:iptv - Enables support for IP TV based devices
media-tv/mythtv:ivtv - Enables ivtv support
media-tv/mythtv:lcd - Enable LCD display support using lcdproc
media-tv/mythtv:opengl - Use OpenGL for vsync
media-tv/mythtv:xvmc - Support for XVideo Motion Compensation (accelerated mpeg playback)
media-tv/tvbrowser:themes - Install extra theme packs
media-tv/xawtv:xext - Enable use of XFree extensions (DGA,VidMode,DPMS)
media-tv/xawtv:zvbi - Enable VBI Decoding Library for Zapping
media-tv/xdtv:aqua_theme - Enable graphic theme Aqua-style
media-tv/xdtv:carbone_theme - Adds the Carbone pixmaps theme for the GUI
media-tv/xdtv:schedule - Adds the possibility to schedule tv recording via xdtv_record.sh
media-tv/xdtv:zvbi - Enable VBI Decoding Library for Zapping
media-tv/xmltv:ar - Argentina tv listing grabber
media-tv/xmltv:be - Belgium and Luxemburg tv listing grabber
media-tv/xmltv:br - Brazil tv listing grabber
media-tv/xmltv:brnet - Brazil cable tv listing grabber
media-tv/xmltv:ch - Switzerland bluewin tv listing grabber
media-tv/xmltv:de_tvtoday - Germany tv listing grabber
media-tv/xmltv:dk - Denmark tv listing grabber
media-tv/xmltv:dtvla - Latin America digital tv listing grabber
media-tv/xmltv:ee - Estonia tv listing grabber
media-tv/xmltv:es - Spain tv listing grabber
media-tv/xmltv:es_laguiatv - Spain alternative grabber
media-tv/xmltv:fi - Finland tv listing grabber
media-tv/xmltv:fr - France tv listing grabber
media-tv/xmltv:hr - Croatia tv listing grabber
media-tv/xmltv:huro - Hungarian tv listing grabber
media-tv/xmltv:il - Israel tv listing grabber
media-tv/xmltv:is - Iceland tv listing grabber
media-tv/xmltv:it - Italy tv listing grabber
media-tv/xmltv:jp - Japan tv listing grabber
media-tv/xmltv:na_dd - North America tv listing grabber
media-tv/xmltv:na_icons - option for na_dd to download icons
media-tv/xmltv:nc - Caledonie Island tv listing grabber
media-tv/xmltv:nl - Netherlands tv listing grabber
media-tv/xmltv:nl_wolf - Netherlands alternative tv listing grabber
media-tv/xmltv:no - Norway tv listing grabber
media-tv/xmltv:no_gf - Norway Gfeed tv listing grabber
media-tv/xmltv:pt - Portugal tv listing grabber
media-tv/xmltv:re - Reunion Island (France) tv listing grabber
media-tv/xmltv:se_swedb - Sweden tv listing grabber
media-tv/xmltv:tv_check - enable GUI checking
media-tv/xmltv:tv_combiner - enable grabbers combiner
media-tv/xmltv:tv_pick_cgi - enable CGI support
media-tv/xmltv:uk_bleb - Britain tv listing grabber
media-tv/xmltv:uk_rt - Britain alternative tv listing grabber
media-tv/xmltv:za - South Africa tv listing grabber
media-tv/zapping:vdr - Enable Real Time Encoding support (librte)
media-tv/zapping:zvbi - Enable VBI Decoding Library
media-video/chaplin:transcode - Enable DVD ripping and transcoding
media-video/cinelerra-cvs:css - Enable support for encrypted files through libmpeg3
media-video/cinepaint:gimpprint - Enable support for gimp-print (gutenprint)
media-video/devede:psyco - psyco python accelerator
media-video/dvd-slideshow:themes - Install theme pack 
media-video/dvdrip:fping - Enables fping support for cluster rendering
media-video/dvdrip:subtitles - Enables support for subtitle ripping
media-video/dxr3player:3dnowext - Enable 3dnowext cpu instructions
media-video/dxr3player:mmxext - Enables mmxext instructions
media-video/ffmpeg:amr - Enables Adaptive Multi-Rate Audio support
media-video/ffmpeg:network - Enables network streaming support
media-video/gpac:amr - Adaptive Multi-Rate Audio support (commonly used in telephony)
media-video/kaffeine:xcb - Support the X C-language Binding, a replacement for Xlib
media-video/kino:gpac - Enable GPAC support when exporting to 3GPP format
media-video/kmplayer:cairo - Support cairo vector graphics library with cross-device output support
media-video/linux-uvc:isight - Apply patch to work _only_ with the Apple iSight
media-video/lives:libvisual - Enable libvisual support
media-video/mjpegtools:yv12 - Enables support for the YV12 pixel format
media-video/mkvtoolnix:lzo - Enables support for lzo compression
media-video/mmsv2:dxr3 - Support for DXR3 mpeg acceleration cards
media-video/motiontrack:multiprocess - Enables multi-process support (SMP/cluster) for motiontrack programs
media-video/mpeg4ip:id3 - Support ID3 in the player
media-video/mpeg4ip:lame - Support LAME mp3 encoding in the server/mp4live
media-video/mpeg4ip:mp4live - Build the live streaming/encoding software
media-video/mpeg4ip:mpeg2 - Support mpeg2 in the player
media-video/mpeg4ip:player - Build the player
media-video/mpeg4ip:v4l2 - Enable video4linux2 support for mp4live
media-video/mplayer:3dnowext - Enable 3dnowext cpu instructions
media-video/mplayer:amrnb - Enables Adaptive Multi-Rate Audio support (Narrow Band)
media-video/mplayer:amrwb - Enables Adaptive Multi-Rate Audio support (Wide Band)
media-video/mplayer:bl - Enables Blinkenlights support in mplayer
media-video/mplayer:cdio - Use libcdio for CD support (instead of cdparanoia)
media-video/mplayer:cpudetection - Enables runtime cpudetection
media-video/mplayer:custom-cflags - Enables custom cflags (not supported)
media-video/mplayer:dvdnav - DVD menu navigation support (not supported)
media-video/mplayer:enca - Enables support for charset discovery and conversion
media-video/mplayer:ivtv - Enable IVTV TV-Out video output
media-video/mplayer:live - Enables live.com streaming media support
media-video/mplayer:lzo - Enables support for lzo compression
media-video/mplayer:md5sum - Enables md5sum video output
media-video/mplayer:mmxext - Enables mmx2 support
media-video/mplayer:mp2 - Enables support for twolame, an MP2 audio library
media-video/mplayer:nemesi - Enable Nemesi Streaming Media support
media-video/mplayer:pnm - Add PNM video output option, to create PPM/PGM/PGMYUV images
media-video/mplayer:pvr - Video4Linux2 MPEG PVR support
media-video/mplayer:radio - Enable V4L2 radio interface and support
media-video/mplayer:rar - Enable Unique RAR File Library
media-video/mplayer:real - Adds real video support
media-video/mplayer:rtc - Enables usage of the linux real time clock.  The alternative is software emulation of rtc
media-video/mplayer:srt - Internal SRT/SSA/ASS (SubRip / SubStation Alpha) subtitle support
media-video/mplayer:ssse3 - faster floating point optimization for SSSE3 capable chips (Intel Core 2 and later chips)
media-video/mplayer:teletext - Support for TV teletext interface
media-video/mplayer:tga - Enables Targa video output
media-video/mplayer:tivo - Enables TiVo vstream client support
media-video/mplayer:v4l2 - Enables video4linux2 support
media-video/mplayer:vidix - Support for vidix video output
media-video/mplayer:xanim - Enables support for xanim based codecs
media-video/mplayer:xvmc - Enables X-Video Motion Compensation support
media-video/mplayer:zoran - Enables ZR360[56]7/ZR36060 video output
media-video/ogmrip:srt - Support for SRT subtitle format
media-video/oxine:polling - Enables support to automatically check the drive for a new disc
media-video/totem:nvtv - Support for nvtv to use tv in on nvidia cards
media-video/transcode:extrafilters - Install some filters only if we ask for them
media-video/transcode:fame - Enables libfame support
media-video/transcode:lzo - Enables support for lzo compression
media-video/transcode:mjpeg - Enables mjpegtools support
media-video/transcode:network - Enables network streaming support
media-video/transcode:nuv - NuppelVideo container format demuxing
media-video/transcode:postproc - Build with ffmpeg libpostproc support
media-video/transcode:v4l2 - Enable video4linux2 support
media-video/vdr:aio - Use "all in one" patch (or its successor "liemikuutio") with much additional features
media-video/vdr:bigpatch - Enables almost all additional features flying around on the net (including aio)
media-video/vdr:child-protection - Enable support for the plugin vdr-pin (Protecting some recordings / channels with a PIN)
media-video/vdr:cmdctrl - allows switching remote control on/off
media-video/vdr:cmdsubmenu - Allows the creation of submenus in the commands menu
media-video/vdr:cutterlimit - Limit IO bandwith used for cutting
media-video/vdr:cutterqueue - Adds a queue of recordings to be cutted
media-video/vdr:ddepgentry - remove duplicate EPG entries
media-video/vdr:cuttime - Adjust starttime of cutted recording by length of cut out parts
media-video/vdr:dolbyinrec - add a dedicated switch to control recording of dolby digital
media-video/vdr:dolby-record-switch - Allows to control separately to record / to replay dolby digital
media-video/vdr:dvbplayer - Use some special mpeg-repacker features. Most usable for old recordings or software output devices.
media-video/vdr:dvbsetup - Setup for AC3 transfer, disable primary tuner
media-video/vdr:dvdarchive - DMH DVD - Archiv ( used by vdr-burn-0.1.0_* )
media-video/vdr:dvdchapjump - Jump on capitels on DMH DVD - Archiv
media-video/vdr:dvlfriendlyfnames - filter file names on recording
media-video/vdr:dvlrecscriptaddon - enhancement for record-script
media-video/vdr:dvlvidprefer - controls video-dir choice on recording
media-video/vdr:dxr3-audio-denoise - Mutes audio noise occurring with dxr3-cards using analog audio-out when e.g. cutting
media-video/vdr:graphtft - support for grapftft plugin up from vdr-graphtft-0.1.7
media-video/vdr:hardlinkcutter - Speed up cutting by hardlinking unchanged files
media-video/vdr:jumpplay - Enables automatic jumping over cut marks while watching a recording
media-video/vdr:liemikuutio - Formerly known as AIO (all-in-one) patch, adds some nice must haves
media-video/vdr:livebuffer - does timeshifting/background recording all the time, allows to rewind live TV
media-video/vdr:lnbshare - Enables support for two or more dvb cards sharing the same cable to the lnb
media-video/vdr:lnbsharing - Enables support for two or more dvb cards sharing the cable to the lnb
media-video/vdr:mainmenuhooks - Allows to replace main menu entries by some special plugins (like epgsearch, extrecmenu, ...)
media-video/vdr:noepg - Adds code to selectively disable epg-reception for specific channels
media-video/vdr:osdmaxitems - Support for text2skin
media-video/vdr:pinplugin - Support for pin plugin
media-video/vdr:rotor - Enable support for plugin vdr-rotor for dish-positioner.
media-video/vdr:settime - set system time per script instead of via syscal
media-video/vdr:setup - Enable support for the plugin vdr-setup
media-video/vdr:setup-plugin - Enable support for the plugin vdr-setup
media-video/vdr:sourcecaps - Adds the ability to define capabilities of dvb-cards (e.g. card1 can receive Sat @28.2E)
media-video/vdr:sortrecords - allows to change sort order of recordings
media-video/vdr:switchtimer - support for timer that do not record but only switch to a channel
media-video/vdr:submenu - Enable support for the plugin vdr-submenu.
media-video/vdr:subtitles - Enable support for the subtitles-plugin
media-video/vdr:syncearly - start live display as soon as possible, not waiting for sync of audio and video
media-video/vdr:timercmd - Adds submenu for user defined commands in timer menu
media-video/vdr:timerinfo - Show with chars +/- if space on HD will suffice for a timer
media-video/vdr:validinput - Signal if it is possible to go left/right in lists with chars < >
media-video/vdr:wareagleicon - Replace original icon set in menu
media-video/vdr:yaepg - Enables support for the plugin vdr-yaepg
media-video/vlc:cdda - Enables libcdda cd audio playback support.
media-video/vlc:corba - Enables corba interface support.
media-video/vlc:daap - Enables DAAP shares services discovery support.
media-video/vlc:dc1394 - Enables IIDC cameras support.
media-video/vlc:httpd - Enables a web based interface for vlc.
media-video/vlc:live - Enables LIVE.com support.
media-video/vlc:mod - Enables Mod demux support.
media-video/vlc:optimisememory - Enable optimisation for memory rather than performance.
media-video/vlc:rtsp - Enables real audio and RTSP modules.
media-video/vlc:sdl-image - Enables sdl image video decoder (depends on sdl)
media-video/vlc:shout - Enables libshout output.
media-video/vlc:skins - Enables support for the skins2 interface.
media-video/vlc:stream - Enables vlc to stream video.
media-video/vlc:upnp - Enables support for Intel UPnP stack.
media-video/vlc:vlm - New videolan (media) manager (vlm), a little manager designed to launch and manage multiple streams from within one instance of VLC.
media-video/winki:css - Enables ripping of encrypted DVDs
media-video/winki:mjpeg - Enables mjpegtools support
media-video/x264-svn-encoder:mp4 - Enables mp4 encoding support
media-video/xine-ui:vdr - Enables Video Disk Recorder support
net-analyzer/aimsniff:http - Install the WAS (Web AIM Sniff) frontend
net-analyzer/barnyard:sguil - Enable sguil (The Analyst Console for Network Security Monitoring) support
net-analyzer/base:signatures - Install community signatures from snort
net-analyzer/bmon:dbi - Enables libdbi support
net-analyzer/bmon:rrdtool - Enables librrd support
net-analyzer/bwm-ng:csv - enable csv output
net-analyzer/bwm-ng:html - enable html output
net-analyzer/cacti:bundled-adodb - use adodb bundled with web-application instead of system wide
net-analyzer/echoping:http - enable support for http protocol.
net-analyzer/echoping:icp - enable support for ICP (used to monitor proxies).
net-analyzer/echoping:priority - enable socket priority support.
net-analyzer/echoping:smtp - enable support for SMTP protocol.
net-analyzer/echoping:tos - enable support for TOS (TYpe Of Service).
net-analyzer/fprobe:messages - enable console messages
net-analyzer/iptraf:suid - Allow app to be run with suid root
net-analyzer/metasploit:httpd - Enable web interface
net-analyzer/munin:munin-apache - installs deps for monitoring apache
net-analyzer/munin:munin-dhcp - installs deps for monitoring DHCP
net-analyzer/munin:munin-irc - installs deps for monitoring IRC
net-analyzer/munin:munin-squid - installs deps for monitoring squid
net-analyzer/munin:munin-surfboard - installs deps for monitoring a Motoro Surfboard Cable modem
net-analyzer/nagios-core:noweb - disable web interface
net-analyzer/nagios-nrpe:command-args - allow clients to specify command arguments
net-analyzer/nagios-plugins:nagios-dns - installs deps for dns monitoring
net-analyzer/nagios-plugins:nagios-game - installs deps for monitoring games-util/qstat
net-analyzer/nagios-plugins:nagios-ntp - installs deps for ntp monitoring
net-analyzer/nagios-plugins:nagios-ping - installs deps for fancy ping monitoring
net-analyzer/nagios-plugins:nagios-ssh - installs deps for monitoring ssh
net-analyzer/nagios-plugins:ups - installs deps for monitoring Network-UPS (sys-power/nut)
net-analyzer/net-snmp:diskio - Enable the use of diskio mibs
net-analyzer/net-snmp:elf - Enable the use of elf utils to check uptime on some sytems
net-analyzer/net-snmp:mfd-rewrites - Use MFD rewrites of mib modules where available
net-analyzer/net-snmp:rpm - Enable the rpm snmp probing
net-analyzer/net-snmp:sendmail - Enable sendmail statistics monitoring
net-analyzer/net-snmp:smux - Enable the smux MIBS module
net-analyzer/pchar:pcap - Use the pcap library
net-analyzer/pmacct:64bit - Use 64bit counters instead of 32bit ones
net-analyzer/rrdtool:rrdcgi - Build rrdcgi support
net-analyzer/sancp:sguil - Enable sguil (The Analyst Console for Network Security Monitoring) support
net-analyzer/scanlogd:nids - Use libnids for package capturing
net-analyzer/scanlogd:pcap - Use libpcap for package capturing
net-analyzer/scapy:gnuplot - Enable gnuplot support
net-analyzer/scapy:pyx - Enable pyx support for psdump/pdfdump commands
net-analyzer/scapy:visual - Enable visual support for 3d graphs
net-analyzer/snort:dynamicplugin - Enable ability to dynamically load preprocessors, detection engine, and rules library
net-analyzer/snort:flexresp - Enable connection tearing (not recommended)
net-analyzer/snort:flexresp2 - Enable new connection tearing
net-analyzer/snort:gre - Enable GRE support
net-analyzer/snort:inline - Enable snort-inline for accepting packets from iptables, via libipq, rather than libpcap.
net-analyzer/snort:linux-smp-stats - Enable statistics reporting through proc on smp systems
net-analyzer/snort:perfprofiling - Enable preprocessor and rule performance profiling
net-analyzer/snort:react - Enable interception and termination of offending HTTP accesses
net-analyzer/snort:sguil - Enable sguil (The Analyst Console for Network Security Monitoring) support
net-analyzer/snort:snortsam - patches snort for use with snortsam
net-analyzer/snort:timestats - Enable TimeStats functionality
net-analyzer/tcpreplay:pcapnav - Enable if you want the jump to byte offset feature via libpcapnav
net-analyzer/zabbix:agent - Enable zabbix agent (for to-be-monitored machines)
net-analyzer/zabbix:frontend - Enable zabbix web frontend
net-analyzer/zabbix:server - Enable zabbix server
net-dialup/bewan-adsl:kt400 - Enable workaround for KT400 motherboards
net-dialup/bewan-adsl:pcitimer - Use 2ms PCI hardware timer
net-dialup/bewan-adsl:slowpcibridge - Enable workaround for low performance PCI bridges
net-dialup/capi4k-utils:fax - Installs capi-fax demo programs
net-dialup/capi4k-utils:pppd - Installs pppdcapiplugin modules
net-dialup/freeradius:edirectory - Enables Novell eDirectory integration
net-dialup/freeradius:frascend - Enables Ascend binary mode
net-dialup/freeradius:frnothreads - Disables thread support
net-dialup/freeradius:frxp - Enables experimental modules
net-dialup/freeradius:udpfromto - Compile in UDPFROMTO support
net-dialup/isdn4k-utils:activefilter - Enable activefilter support for ipppd
net-dialup/isdn4k-utils:eurofile - Support for EUROFILE Transfer Protocol
net-dialup/isdn4k-utils:ipppd - Build the (ISDN) PPP daemon for synchronous PPP for ISDN connections
net-dialup/isdn4k-utils:isdnlog - Install the isdn log system
net-dialup/isdn4k-utils:mschap - Enable Microsoft chap authentication for ipppd
net-dialup/ivcall:softfax - Enables soft fax support
net-dialup/mgetty:fidonet - Enables FidoNet support
net-dialup/misdn:ecaggressive - Make the selected echo canceller a little more aggressive
net-dialup/misdn:eckb1 - Use the KB1 echo canceller
net-dialup/misdn:ecmark2 - Use the MARK2 echo canceller
net-dialup/misdn:ecmg2 - Use the MG2 echo canceller (default)
net-dialup/ppp:activefilter - Enables activefilter support
net-dialup/ppp:atm - Enables support for PPP over ATM (PPPoA)
net-dialup/ppp:dhcp - Enables the DHCP plugin
net-dialup/ppp:eap-tls - Enables support for Extensible Authentication Protocol and Transport Level Security (EAP-TLS)
net-dialup/ppp:mppe-mppc - Enables support for MPPE-MPPC
net-dialup/pptpd:gre-extreme-debug - Log all GRE accepted packages when in debug mode (required if you want upstream support)
net-dns/avahi:autoipd - Build and install the IPv4LL (RFC3927) network address configuration daemon
net-dns/avahi:bookmarks - Install the avahi-bookmarks application (requires dev-python/twisted)
net-dns/avahi:howl-compat - Enable compat libraries for howl
net-dns/avahi:mdnsresponder-compat - Enable compat libraries for mDNSResponder
net-dns/bind:bind-mysql - enables mysql support for bind (non-dlz)
net-dns/bind:dlz - enables dynamic loaded zones, 3rd party extension
net-dns/bind:resolvconf - enable support for net-dns/resolvconf
net-dns/bind:urandom - Use /dev/urandom instead of /dev/random
net-dns/djbdns:aliaschain - enables a fix for the truncation of alias chains
net-dns/djbdns:cnamefix - changes the CNAME behavior of dnscache
net-dns/djbdns:datadir - enables tinydns-data to read a directory with multiple data files
net-dns/djbdns:fwdonly - enable JBP's dnscache-strict-forwardonly patch
net-dns/djbdns:fwdzone - enables forward zone patch
net-dns/djbdns:multidata - enables command line parameters for tinydns-data to specify the data file(s)
net-dns/djbdns:multipleip - enables multi-IP patch
net-dns/djbdns:roundrobin - enables round robin patch
net-dns/djbdns:semanticfix - makes tinydns-data handle more semantic errors
net-dns/dnsmasq:isc - enable support for reading ISC DHCPd lease files
net-dns/dnsmasq:resolvconf - enable support for net-dns/resolvconf
net-dns/dnsmasq:tftp - enables built in TFTP server for netbooting
net-dns/pdns:opendbx - Enable the OpenDBX backend
net-dns/pdns:tdb - Enable the Trivial Database (xdb) backend
net-dns/pdnsd:isdn - Enable ISDN features
net-dns/pdnsd:underscores - Enable support for domain names containing underscores
net-firewall/ipsec-tools:hybrid - Makes available both mode-cfg and xauth support
net-firewall/ipsec-tools:idea - Enable support for the patented IDEA algorithm
net-firewall/ipsec-tools:nat - Enable NAT-Traversal
net-firewall/ipsec-tools:rc5 - Enable support for the patented RC5 algorithm
net-firewall/iptables:extensions - Enable support for 3rd patch-o-matic extensions
net-firewall/iptables:imq - Enable support for intermediate queueing devices (http://www.linuximq.net)
net-firewall/iptables:l7filter - Enable support for layer 7 filtering (http://l7-filter.sourceforge.net)
net-firewall/nufw:ident - Add support ident for users authentication
net-firewall/nufw:nfconntrack - Use netfilter_conntrack
net-firewall/nufw:nfqueue - Use NFQUEUE instead of QUEUE
net-firewall/nufw:pam_nuauth - Add support for pam nufw from PAM
net-firewall/nufw:plaintext - Add support for authentication with plaintext file
net-firewall/nufw:syslog - Add support user activity logging in syslog
net-fs/netatalk:xfs - Enable support for XFS Quota
net-fs/nfs-utils:nonfsv4 - Disable support for NFSv4
net-fs/samba:ads - Enable Active Directory support
net-fs/samba:async - Enables asynchronous input/output
net-fs/samba:automount - Enables automount support
net-fs/samba:oav - Enables support for anti-virus from the openantivirus.org project
net-fs/samba:quotas - Enables support for user quotas
net-fs/samba:swat - Enables support for swat configuration gui
net-fs/samba:syslog - Enables support for syslog
net-fs/samba:winbind - Enables support for the winbind auth daemon
net-fs/shfs:amd - Enable automounter support
net-ftp/ftpcube:sftp - Enable sftp connection support
net-ftp/proftpd:authfile - Enable support for auth-file module
net-ftp/proftpd:ifsession - Enable support for the ifsession module
net-ftp/proftpd:noauthunix - Disable support for auth-unix module
net-ftp/proftpd:opensslcrypt - Enable support for openssly crypto
net-ftp/proftpd:rewrite - Enable support for rewrite module
net-ftp/proftpd:shaper - Enable support for the mod_shaper
net-ftp/proftpd:sitemisc - Enable support for sitemisc module
net-ftp/proftpd:softquota - Enable support for the mod_quotatab
net-ftp/proftpd:vroot - Enable support for virtual root module
net-ftp/pure-ftpd:charconv - Enables charset conversion
net-ftp/pure-ftpd:noiplog - Disables logging of IP addresses
net-ftp/pure-ftpd:paranoidmsg - Display paranoid messages instead of normal ones
net-ftp/pure-ftpd:vchroot - Enable support for virtual chroot (possible security risk)
net-ftp/vsftpd:logrotate - Use logrotate for rotating logs
net-im/bitlbee:msnextras - Enables extra MSN patches not supported by upstream
net-im/bitlbee:nss - Use NSS for SSL support in MSN and Jabber.
net-im/bitlbee:openssl - Use OpenSSL for SSL support in MSN and Jabber.
net-im/centericq:irc - Enable support for the IRC protocol
net-im/centericq:lj - Enable support for the LiveJournal weblog system
net-im/centericq:rss - Enable support for RSS/RDF feeds
net-im/centerim:gadu - Enable support for the Gadu-Gadu protocol
net-im/centerim:irc - Enable support for the IRC protocol
net-im/centerim:lj - Enable support for the LiveJournal weblog system
net-im/centerim:rss - Enable support for RSS/RDF feeds
net-im/ejabberd:mod_irc - Irc support in ejabberd
net-im/ejabberd:mod_muc - Multi user chat support in ejabberd
net-im/ejabberd:mod_pubsub - Pubsub support in ejabberd
net-im/ejabberd:sname - Use -sname instead of -name to launch the ejabberd beam
net-im/ejabberd:statsdx - Collect (much) more detailed statistics
net-im/ejabberd:web - Web support in ejabberd
net-im/ekg2:gsm - Enable gsm plugin
net-im/ekg2:nogg - Disable Gadu-Gadu plugin
net-im/gaim:bonjour - Enable bonjour support
net-im/gaim:console - Enable gaim-text
net-im/gaim:custom-cflags - Disables stripping of "unsafe C[XX]FLAGS"
net-im/gaim:gadu - Enable Gadu Gadu protocol support.
net-im/gaim:groupwise - Enable Novell Groupwise protocol support.
net-im/gaim:meanwhile - Enable meanwhile support for Sametime protocol.
net-im/gaim:qq - Enable QQ protocol support.
net-im/gaim:silc - Enable SILC protocol support
net-im/gajim:idle - Enable idle module
net-im/gajim:srv - SRV capabilities
net-im/gajim:trayicon - Enable support for trayicon
net-im/gajim:xhtml - Enable XHTML support
net-im/gnugadu:tlen - Enable Tlen.pl protocol support
net-im/gossip:galago - Enable desktop presence with galago
net-im/jabberd:memdebug - Enable nad and pool debug
net-im/jabberd:pipe - Enable pipe auth
net-im/kadu:amarok - Enables amarok support in kadu
net-im/kadu:config_wizard - Enables configuration wizard module
net-im/kadu:extraicons - Enables extra icon sets
net-im/kadu:extramodules - Enables extra module in kadu
net-im/kadu:mail - Enables mail module in kadu
net-im/kadu:speech - Enables speech module in kadu
net-im/kadu:voice - Enables voice chat in kadu
net-im/naim:screen - Enable screen support
net-im/pidgin:bonjour - Enable bonjour support
net-im/pidgin:gadu - Enable Gadu Gadu protocol support.
net-im/pidgin:groupwise - Enable Novell Groupwise protocol support.
net-im/pidgin:meanwhile - Enable meanwhile support for Sametime protocol.
net-im/pidgin:networkmanager - Enable networkmanager support
net-im/pidgin:prediction - Enable Contact Availability Prediction plugin.
net-im/pidgin:qq - Enable QQ protocol support.
net-im/pidgin:silc - Enable SILC protocol support
net-im/pidgin:zephyr - Enable Zephyr protocol support
net-im/psi:audacious - Enable monitoring of audio tracks that are played in (media-sound/audacious)
net-im/psi:extras - Enables extra non official patches
net-im/psi:insecure-patches - Enables extra non official patches that may pose as a security risk
net-im/psi:jingle - Enables voice calls for jabber
net-im/psi:plugins - Enables plugins support in psi
net-im/pyaim-t:webinterface - Install dependencies needed for the web interface
net-im/pyicq-t:webinterface - Install dependencies needed for the web interface
net-im/skype:qt-static - Installs binaries statically linked to Qt
net-im/tkabber:extras - Enables extra non official patches
net-im/tkabber:plugins - Enables instalation the extra plugins
net-im/tmsnc:talkfilters - Enables Talkfilters support on tmsnc
net-im/twinkle:ilbc - Enables use of ilbc (RFC3951) audio encoding
net-im/twinkle:zrtp - Enables use of secure rtp using the zrtp extension of GNU RTP stack developed by Phil Zimmermen
net-irc/atheme:largenet - Enable support/tweaks for large networks
net-irc/charybdis:smallnet - Enables support for smaller IRC networks
net-irc/eiwic:rss - Enables support for RSS feeds
net-irc/inspircd:openssl - Build OpenSSL module
net-irc/ircd-hybrid:contrib - Build contrib modules (eg. cloaking)
net-irc/ngircd:ident - Enables support for libident
net-irc/srvx:bahamut - Choose bahamut protocol over p10 protocol
net-irc/unrealircd:hub - Enable hub support
net-irc/unrealircd:prefixaq - Enable chanadmin and chanowner prefixes
net-irc/unrealircd:showlistmodes - support displaying channel modes during compilation
net-irc/xchat-gnome:libsexy - Enable libsexy support
net-irc/xchat-xsys:audacious - Enables Audacious (media player) integration
net-irc/xchat-xsys:buttons - Enables the buttons near the nickname list
net-irc/xchat:xchatdccserver - Enables support for the /dccserver command via a patch
net-irc/xchat:xchatnogtk - Disables building the GTK front end to XChat
net-irc/znc:nomodules - Don't build modules
net-libs/aqbanking:chipcard - Enable support for DDV/RSA-chipcards
net-libs/aqbanking:dtaus - Enable dtaus backend
net-libs/aqbanking:geldkarte - Enable geldkarte backend
net-libs/aqbanking:hbci - Enable support for HBCI
net-libs/aqbanking:yellownet - Enable support for Yellownet
net-libs/courier-authlib:vpopmail - Enable vpopmail support
net-libs/gnutls:lzo - Enables support for lzo compression
net-libs/libetpan:liblockfile - Enable support for liblockfile library
net-libs/libfwbuilder:stlport - Enagle support for STLport
net-libs/libpri:bri - Enable ISDN BRI support (bristuff)
net-libs/libssh2:libgcrypt - Use libgcrypt for crypto
net-libs/libvncserver:no24bpp - disable 24bpp support
net-libs/libvncserver:nobackchannel - disable backchannel support
net-libs/opal:noaudio - Disable audio codecs
net-libs/opal:novideo - Disable video codecs
net-libs/openh323:noaudio - Disable audio codecs
net-libs/openh323:novideo - Disable video codecs
net-mail/cyrus-imapd:autocreate - Enable not supported (by upstream) patch from University of Athens for automatic creation of user mailboxes
net-mail/cyrus-imapd:autosieve - Enable not supported (by upstream) patch from University of Athens for "on demand" creation of any folder requested by a sieve filter
net-mail/cyrus-imapd:drac - Enable dynamic relay support in the cyrus imap server
net-mail/cyrus-imapd:idled - Enable idled vs poll IMAP IDLE method
net-mail/cyrus-imapd:unsupported_8bit - Enable 8bit not supported patch
net-mail/cyrus-imapd:replication - Enable replication support in the cyrus imap server
net-mail/dbmail:sieve - Enable sieve filter support
net-mail/dovecot:pop3d - Build pop3d support
net-mail/dovecot:sieve - Build the sieve plugin
net-mail/dovecot:suid - Install the deliver binary suid, acknowledging the usual risks
net-mail/dovecot:vpopmail - Add vpopmail support
net-mail/fetchmail:hesiod - Enable support for hesiod
net-mail/gnubiff:password - Enable save passwords to connect mail servers in user space
net-mail/hotwayd:smtp - Build SMTP proxy (hotsmtpd)
net-mail/lbdb:abook - Enables app-misc/abook support
net-mail/lbdb:finger - Enables finger support
net-mail/mailgraph:logrotate - Install logrotate script for clamav logs
net-mail/mailman:courier - Build with delivery options for courier
net-mail/mailman:exim - Build with delivery options for exim
net-mail/mailman:postfix - Build with delivery options for postfix
net-mail/mailman:qmail - Build with delivery options for qmail
net-mail/mailman:sendmail - Build with delivery options for sendmail
net-mail/mailman:xmail - Build with delivery options for xmail
net-mail/qmailadmin:maildrop - Filter spam using maildrop
net-mail/qpopper:mailbox - Enables mail spool file is in home directory ~/Mailbox
net-mail/teapop:virtual - Enable teapop's virtual domain support.
net-mail/uw-imap:clearpasswd - Enables cleartext logins outside of SSL sessions
net-mail/vimap:clearpasswd - Enables cleartext logins outside of SSL sessions
net-mail/vpopmail:clearpasswd - Enables cleartext password storage in the vpasswd files
net-mail/vpopmail:ipalias - Enables enable-ip-alias-domains
net-mail/vpopmail:maildrop - Enables maildrop support in vdelivermail
net-misc/aria2:ares - Enables support for asynchronous DNS using the c-ares library
net-misc/aria2:bittorrent - Enables support for the bittorrent protocol
net-misc/aria2:metalink - Enables support for metalink
net-misc/asterisk-addons:h323 - Build the chan_ooh323c H.323 channel driver
net-misc/asterisk-chan_capi:fax - Build chan_capi with fax support
net-misc/asterisk:bri - Enable ISDN BRI support (bristuff)
net-misc/asterisk:genericjb - Enable experimental generic jitter buffer
net-misc/asterisk:h323 - Build the H.323 channel driver bundled with Asterisk
net-misc/asterisk:lowmem - Build Asterisk for environments with low amounts of memory (embedded devices)
net-misc/asterisk:mysqlfriends - Enable MySQL friends support in chan_sip
net-misc/asterisk:nosamples - Don't install sample sound and configuration files
net-misc/asterisk:osp - Enable support for the Open Settlement Protocol
net-misc/asterisk:pri - Enables pri support (>=asterisk-1.0.1)
net-misc/asterisk:resperl - Enables support for embedded perl in extensions.conf
net-misc/asterisk:ukcid - Enable UK callerid support
net-misc/asterisk:vmdbmysql - Enable mysql db support in voicemail application
net-misc/asterisk:vmdbpostgres - Enable postgres db support in voicemail application
net-misc/asterisk:zaptel - Enables zaptel support (>=asterisk-1.0.1)
net-misc/bird:client - Enables the BIRD client
net-misc/bird:ipv6only - Builds with only IPv6, note that this *disables* IPv4 entirely
net-misc/bridge-utils:sysfs - Enable use of the sysfs filesystem (Linux-2.6+) via libsysfs
net-misc/curl:ares - Enabled c-ares dns support
net-misc/curl:libssh2 - Enabled SSH urls in curl using libssh2
net-misc/curl:nss - Use NSS as the crypto engine
net-misc/dhcpcd:vram - Disable DUID due to volatile media, such as a LiveCD
net-misc/directvnc:mouse - Adds mouse support
net-misc/drivel:rhythmbox - Enables support for currently playing song in rhythmbox
net-misc/dropbear:multicall - Build all the programs as one little binary (to save space)
net-misc/gwget:epiphany - Build epiphany extensions
net-misc/hamachi:pentium - Add support for older Pentium based systems
net-misc/htbinit:esfq - Add support for Enhanced Stochastic Fairness queueing discipline.
net-misc/hylafax:faxonly - Don't depend on mgetty-fax
net-misc/hylafax:html - Adds HTML documentation
net-misc/hylafax:mgetty - Adds support for mgetty and vgetty
net-misc/icecast:yp - Build support for yp public directory listings
net-misc/kvpnc:cisco - Adds support for Cisco client
net-misc/ntp:zeroconf - Add support for multicast dns
net-misc/ntp:openntpd - Allow ntp to be installed alongside openntpd
net-misc/ntp:parse-clocks - Add support for PARSE clocks
net-misc/nx:vnc - Add support for vnc to remote servers
net-misc/nxnode:vnc - Add support for vnc to remote servers
net-misc/nxserver-2xterminalserver:vnc - Add support for vnc to remote servers
net-misc/nxserver-freenx:nxclient - Add support for the commercial nxclient
net-misc/oidentd:masquerade - Enable support for masqueraded/NAT connections
net-misc/openssh:X509 - Adds support for X.509 certificate authentication
net-misc/openssh:chroot - Enable chrooting support
net-misc/openssh:hpn - Enable high performance ssh
net-misc/openswan:extra-algorithms - Include additional algorithms such as Blowfish, Twofish and Serpent
net-misc/openswan:weak-algorithms - Include weak algorithms such as DH1 and 1DES
net-misc/openvpn:iproute2 - Enabled iproute2 support instead of net-tools
net-misc/openvpn:passwordsave - Enables openvpn to save passwords
net-misc/partysip:syslog - Enable syslog support
net-misc/quagga:bgpas4 - Enable support for 32-bit AS numbers
net-misc/quagga:bgpclassless - Enable classless prefixes for BGP
net-misc/quagga:fix-connected-rt - Remove interface connected routes from kernel table on link loss so that no packets get routed to downed interface
net-misc/quagga:multipath - Enable multipath routes support for any number of routes
net-misc/quagga:ospfapi - Enable OSPFAPI support for client applications accessing the OSPF link state database
net-misc/quagga:realms - Enable realms support (see http://vcalinus.gemenii.ro/quaggarealms.html)
net-misc/quagga:tcp-zebra - Enable TCP zserv interface on port 2600 for Zebra/protocol-daemon communication. Unix domain sockets are choosen otherwise.
net-misc/quagga:tcpmd5 - Enable TCP MD5 checksumming
net-misc/scponly:subversion - Enable support for the subversion version control system
net-misc/sitecopy:gssapi - Enables GSSAPI (Generic Security Services Application Programming Interface).  This is a client-server authentication method that promotes a standard API for authentication systems.  This is included in kerbos distributions and allows vendors to define a specific system with a more generic API layer to coordinate with other authentication systems.
net-misc/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 prefered.
net-misc/sitecopy:sftp - Enables use of sftp for secure ftp transfers.
net-misc/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.
net-misc/ssh:openssh - Allow ssh and openssh to be installed side by side
net-misc/streamtuner:shout - Enable shoutcast plug-in.
net-misc/streamtuner:xiph - Enable xiph.org plug-in.
net-misc/strongswan:nat - Enable NAT-Traversal on Transport Mode (insecure)
net-misc/tightvnc:server - Build vncserver. Allows us to only build server on one machine if set, build only viewer otherwise.
net-misc/tsclient:vnc - Adds vncviewer support.
net-misc/vino:keyring - Enable gnome-keyring support for storing passwords
net-misc/vnc:server - Build VNC server
net-misc/vpnc:hybrid-auth - Enable hybrid authentication (certificates), only if not redistributed as compiled binary
net-misc/vtun:lzo - Enables support for lzo compression
net-misc/wanpipe:adsl - Build with adsl support
net-misc/xf4vnc:vncviewer - Install the vncviewer binary
net-misc/xf4vnc:xvnc - Install the Xvnc binary
net-misc/xsupplicant:gsm - Add support for EAP-SIM authentication algorithm
net-misc/zaptel:astribank - Install Xorcom Astribank utilities
net-misc/zaptel:bri - Enable ISDN BRI support (bristuff)
net-misc/zaptel:devfs26 - Devfs support for Linux-2.6
net-misc/zaptel:ecaggressive - Make the mark2 echo canceller a little more aggressive
net-misc/zaptel:eckb1 - Use the KB1 echo canceller
net-misc/zaptel:ecmark - Use the MARK echo canceller
net-misc/zaptel:ecmark2 - Use the MARK2 echo canceller (default)
net-misc/zaptel:ecmark3 - Use the MARK3 echo canceller
net-misc/zaptel:ecmg2 - Use the MG2 echo canceller
net-misc/zaptel:ecoslec - Use the OSLEC echo canceller (http://www.rowetel.com/ucasterisk/oslec.html)
net-misc/zaptel:ecsteve - Use the STEVE echo canceller
net-misc/zaptel:ecsteve2 - Use the STEVE2 echo canceller
net-misc/zaptel:florz - Enable florz enhancement patches for ISDN BRI
net-misc/zaptel:rtc - Use the realtime clock on x86 and amd64 systems instead of kernel timers
net-misc/zaptel:ukcid - Enable UK callerid support
net-misc/zaptel:watchdog - Enable the watchdog to monitor unresponsive and misbehaving interfaces
net-misc/zaptel:zapnet - Enable SyncPPP, CiscoHDLC and Frame-Relay support
net-misc/zaptel:zapras - Enable PPP support for Remote-Access-Service
net-nds/openldap:overlays - Enable contributed OpenLDAP overlays
net-nds/openldap:smbkrb5passwd - Enable overlay for syncing ldap, unix and lanman passwords
net-nds/tac_plus:finger - Adds support for checking user counts via fingering the NAS
net-news/liferea:networkmanager - Enable networkmanager support
net-nntp/inn:innkeywords - Enable automatic keyword generation support
net-nntp/inn:inntaggedhash - Use tagged hash table for history (disables large file support)
net-nntp/slrn:uudeview - Add support for yEnc coding and more using dev-libs/uulib
net-p2p/amule:amuled - enable amule daemon
net-p2p/amule:remote - enable remote controlling of the client
net-p2p/amule:stats - enable statistic reporting
net-p2p/gift:ares - pull in Ares plugin
net-p2p/gift:fasttrack - pull in FastTrack plugin
net-p2p/gift:gnutella - pull in Gnutella plugin
net-p2p/gift:openft - pull in OpenFT plugin
net-p2p/linkage:upnp - Enables support for Intel UPnP stack.
net-p2p/linkage:xfce - Adds Xfce4 support
net-p2p/mldonkey:fasttrack - enable fasttrack support
net-p2p/mldonkey:gnutella - enable gnutella and gnutella2 support
net-p2p/mldonkey:guionly - enable client build only
net-p2p/mldonkey:magic - enable use of libmagic
net-p2p/museek+:qsa - Enable QSA scripting for museeq
net-p2p/museek+:trayicon - Enable support for trayicon
net-p2p/transmission:daemon - Enable data collection daemon
net-print/hplip:fax - Enable fax support
net-print/hplip:parport - Enable parallel port support
net-print/omni:epson - include the epson drivers
net-print/pkpgcounter:psyco - psyco python accelerator
net-proxy/dansguardian:kaspersky - Adds support for Kaspersky AntiVirus software
net-proxy/dansguardian:ntlm - Enable support for the NTLM auth plugin
net-proxy/squid:ipf-transparent - Adds transparent proxy support for systems using IP-Filter (only for *bsd)
net-proxy/squid:logrotate - Use logrotate for rotating logs
net-proxy/squid:pf-transparent - Adds transparent proxy support for systems using PF (only for *bsd)
net-proxy/squid:qos - Adds tcp_outgoing_priority for setting the Qdisc priority
net-proxy/squid:zero-penalty-hit - Adds Zero Penalty Hit patch (http://zph.bratcheda.org/)
net-proxy/sshproxy:client-only - Install only the client wrappers
net-proxy/tinyproxy:transparent-proxy - Enables support for transparent proxies
net-proxy/tsocks:tordns - Apply tordns patch which allows transparent TORification of the DNS queries
net-voip/linphone:console - Build console interface
net-voip/linphone:ilbc - Build ILBC codec plugin
net-voip/linphone:novideo - Disable video support
net-voip/yate:gsm - Build gsm codec plugin
net-voip/yate:h323 - Build H.323 Channel plugin
net-voip/yate:ilbc - Build ILBC codec plugin
net-voip/yate:zaptel - Build zaptel Channel plugin
net-wireless/bluez-utils:old-daemons - Install old daemons like hidd and sdpd that are deprecated by the new Service framework
net-wireless/bluez-utils:test-programs - Install l2test and rctest
net-wireless/hostapd:logwatch - Install support files for logwatch
net-wireless/hostapd:madwifi - Add support for madwifi (Atheros chipset)
net-wireless/iwlwifi:ipw3945 - Add support for the IPW3945 wireless card
net-wireless/iwlwifi:ipw4965 - Add support for the IPW4965 wireless card
net-wireless/kdebluetooth:irmc - Enable the kitchensync(Multisynk)'s IrMCSync konnector
net-wireless/madwifi-ng:injection - Adds support for aircrack-ng aireplay-ng packet-injection
net-wireless/madwifi-old:amrr - Use Adaptive Multi Rate Retry bit rate control algorithm
net-wireless/madwifi-old:onoe - Use Atsushi Onoe's bit rate control algorithm
net-wireless/rt2x00:asm - Build ASM files
net-wireless/rt2x00:rfkill - Enable radio button support
net-wireless/rt2x00:rt2400pci - Build rt2400pci driver
net-wireless/rt2x00:rt2500pci - Build rt2500pci driver
net-wireless/rt2x00:rt2500usb - Build rt2500usb driver
net-wireless/rt2x00:rt61pci - Build rt61pci driver
net-wireless/rt2x00:rt73usb - Build rt73usb driver
net-wireless/wepattack:john - Build with johntheripper support
net-wireless/wifiscanner:wireshark - use wireshark's wtap library
net-wireless/wireless-tools:multicall - Build the most commonly used tools as one binary
net-wireless/wpa_supplicant:gsm - Add support for EAP-SIM authentication algorithm
net-wireless/wpa_supplicant:madwifi - Add support for madwifi (Atheros chipset)
net-www/gnash:agg - Rendering based on the Anti-Grain Geometry Rendering Engine library
net-www/mplayerplug-in:divx - Divx Playback Support
net-www/mplayerplug-in:gmedia - Google Media Playback Support
net-www/mplayerplug-in:mplayer-bin - Use binary mplayer for 32 bit codecs on amd64
net-www/mplayerplug-in:realmedia - Real Media Playback Support
net-www/mplayerplug-in:wmp - Windows Media Playback Support
rox-extra/archive:ace - Enable .ace support via unace package
rox-extra/archive:compress - Enable tar.Z and *.Z via ncompress package
rox-extra/archive:cpio - Enable .cpio extraction via cpio package
rox-extra/archive:rar - Enable .rar support via rar package
rox-extra/archive:rpm - Enable .rpm extraction via rpm2cpio from the rpm package
rox-extra/archive:uuencode - Enable .uue compression/decompression via sharutils package
rox-extra/archive:zip - Enable .zip support via zip and unzip packages
rox-extra/comicthumb:rar - Enable support for rar-compressed archives
rox-extra/magickthumbnail:xcf - Enable previews of .xcf files using the gimp
sci-astronomy/orsa:cln - Use the Class Library for Numbers for calculations
sci-astronomy/predict:xforms - Add a "map" client which uses the xforms library for its GUI
sci-astronomy/predict:xplanet - Project predict data onto world maps generated by xplanet/xearth
sci-astronomy/setiathome:server - Enable compilation of server
sci-biology/biopython:kdtree - Do not build KDTree module and its dependencies (NeighborSearch)
sci-biology/clustalw-mpi:mpi_njtree - Use MPI (as opposed to serial) code for computing neighbor-joining trees
sci-biology/clustalw-mpi:static_pairalign - Use static (as opposed to dynamic) scheduling for pair alignments
sci-biology/hmmer:pvm - Add support for parallel virtual machine.
sci-biology/vienna-rna:no-readseq - Do not include the modified version of Don Gilbert's readseq program
sci-biology/vienna-rna:no-utils - Do not include sequence format conversion and representation utilities
sci-chemistry/caver:pymol - Install the PyMol plugin
sci-chemistry/coot:new-interface - Build with the experimental GTK+-2 interface instead of GTK+-1
sci-chemistry/eden:double-precision - more precise calculations at the expense of speed
sci-chemistry/ghemical:gamess - Add GAMESS interface for QM/MM.
sci-chemistry/ghemical:mopac7 - Apply compilation fix for mopac7 support.
sci-chemistry/ghemical:openbabel - Use the OpenBabel package for file conversions
sci-chemistry/ghemical:toolbar - Build the shortcuts toolbar
sci-chemistry/gromacs:double-precision - more precise calculations at the expense of speed
sci-chemistry/jmol:client-only - Install the viewer only, no applet files for httpd.
sci-chemistry/jmol:vhosts - Install jmol applet files into a virtual hosting environment.
sci-chemistry/shelx:dosformat - Use CR/LF to end lines; useful in mixed Linux/Windows environments
sci-electronics/gwave:gnuplot - Enable gnuplot support
sci-geosciences/gmt:gmtfull - Full resolution bathymetry database
sci-geosciences/gmt:gmthigh - Adds high resolution bathymetry database
sci-geosciences/gmt:gmtsuppl - Supplement functions for GMT
sci-geosciences/gmt:gmttria - Non GNU triangulation method, more efficient
sci-geosciences/gpsd:italk - Enable iTalk protocol support
sci-geosciences/gpsd:itrax - Enable iTrax hardware support
sci-geosciences/gpsd:ntp - Enable NTP shared memory interface for GPS time
sci-geosciences/gpsd:tntc - Enable True North Technologies support
sci-geosciences/grass:gdal - Enables gdal support (Grass 6 only)
sci-geosciences/grass:glw - Enables libGLw support (requires mesa)
sci-geosciences/grass:gmath - Enables gmath wrapper for BLAS/Lapack
sci-geosciences/grass:largefile - Enables LFS support for huge files
sci-geosciences/mapserver:agg - Enables agg library support
sci-geosciences/mapserver:flash - Adds support for creating SWF files using Ming
sci-geosciences/mapserver:gdal - Enables gdal library support
sci-geosciences/mapserver:geos - Enables geos library support
sci-geosciences/mapserver:postgis - Enables postgis support 
sci-geosciences/mapserver:proj - Enables proj library support (geographic projections)
sci-libs/acml:openmp - Install the OpenMP parallel computing library as well (needs ifc or gfortran-4.2!!)
sci-libs/acml:int64 - Install the 64 bits integer library.
sci-libs/fftw:float - Links default library to single precision instead of double (symlinks only)
sci-libs/gdal:fits - Enables support for NASA's cfitsio library
sci-libs/gdal:geos - Adds support for geometry engine
sci-libs/gdal:gml - Enables support for xerces-c API
sci-libs/gdal:hdf - Adds support for the Hierarchical Data Format
sci-libs/gdal:hdf5 - Adds support for the Hierarchical Data Format v 5
sci-libs/gdal:ogdi - Enables support for the open geographic datastore interface
sci-libs/gerris:dx - Enables support for opendx
sci-libs/hdf5:cxx - Builds C++ library support (conflicts with mpi support)
sci-libs/hdf5:f90 - Flag to override fortran for externel compilers
sci-libs/hdf5:hlapi - Enables support for high-level library
sci-libs/itpp:cblas - Adds support for the cblas numerical library
sci-libs/libghemical:mopac7 - Use the MOPAC7 package for semi-empirical calculations
sci-libs/libghemical:mpqc - Use the MPQC package for quantum-mechanical calculations
sci-libs/mkl:fortran95 - Add support for a Fortran95 BLAS/LAPACK interface
sci-libs/plplot:itcl - Support for itcl bindings.
sci-libs/plplot:octave - Support for Octave bindings.
sci-libs/scipy:sandbox - Installs experimental scipy sandbox modules (pull some dependencies)
sci-libs/scipy:umfpack - Add support for sparse solving via UMFPACK
sci-libs/vtk:patented - Builds patented classes.
sci-mathematics/coq:ide - Build the Coq IDE, a clone of proof general using lablgtk2.
sci-mathematics/coq:norealanalysis - Do not build real analysis modules (faster compilation).
sci-mathematics/coq:translator - Install the translator script from coq-7.4 to coq-8.0, and its documentation if doc is set too.
sci-mathematics/drgeo:no-helpbrowser - Do not install the default help browser
sci-mathematics/freemat:arpack - Add sparse eigen value support via arpack
sci-mathematics/freemat:ffcall - Enables uses of ffcall
sci-mathematics/freemat:umfpack - Add sparse solving via umfpack
sci-mathematics/geomview:avg - Enable experimental motion averaging technique
sci-mathematics/geomview:netpbm - Add NetPBM support for external modules
sci-mathematics/maxima:auctex - enable auctex in maxima
sci-mathematics/maxima:clisp - adds clisp support to maxima
sci-mathematics/maxima:cmucl - adds cmucl (lisp) support to maxima
sci-mathematics/maxima:gcl - adds gcl (lisp) support to maxima
sci-mathematics/maxima:sbcl - adds sbcl (lisp) support to maxima
sci-mathematics/mupad:mupad-noscilab - Disable scilab that comes with MuPAD package. Use system-wide instead.
sci-mathematics/nusmv:minisat - Enable support for MiniSat.
sci-mathematics/octave-forge:qhull - Adds media-libs/qhull (geometric extensions) support
sci-mathematics/octave:hdf5 - Adds support for the Hierarchical Data Format v5 to sci-mathematics/octave (may be merged with hdf when opendx is completed)
sci-mathematics/singular:boost - Compile against external boost headers.
sci-mathematics/yacas:server -  Build the network server version.
sci-misc/boinc:server - Enable compilation of server
sci-misc/h5utils:octave - Build Octave plugins
sci-misc/nco:ncap2 - Build next generation netcdf arithmetic processor (needs dev-java/antlr)
sci-misc/nco:udunits - Add udunits files support
sci-misc/ncview:udunits - Add udunits files support
sci-physics/root:cern - Add cernlib i/o functionality to root
sci-visualization/gnuplot:xemacs - Add support for XEmacs
sci-visualization/hippodraw:fits - Add FITS support to hippodraw, via cfitsio
sci-visualization/hippodraw:numarray - Add numarray python array support
sci-visualization/hippodraw:root - Add root i/o, and minuit support
sci-visualization/labplot:cdf - Adds cdf data exchange format support
sci-visualization/labplot:kexi - Import and export data from/to MySQL, PostgreSQL etc. via Kexi (app-office/kexi).
sci-visualization/opendx:cdf - Adds cdf data exchange format support
sci-visualization/opendx:hdf - Adds support for the Hierarchical Data Format
sci-visualization/paraview:hdf5 - Adds support for the Hierarchical Data Format v5
sec-policy/selinux-desktop:avahi - Add avahi SELinux policy.
sys-apps/acl:nfs - add support for NFS acls
sys-apps/busybox:make-symlinks - Create all the appropriate symlinks in /bin and /sbin
sys-apps/busybox:savedconfig - Adds support to user defined configs
sys-apps/coreutils:xattr - if you want extended attributes enabled
sys-apps/hal:dell - Adds support for Dell laptop smbios via libsmbios
sys-apps/hal:disk-partition - Add support for partition editing via libparted
sys-apps/hal:dmi - Adds support for DMI (Desktop Management Interface)
sys-apps/hwdata-gentoo:binary-drivers - Adds support for ATI/NVIDIA binary drivers
sys-apps/iproute2:atm - Add support for ATM qdisc manager
sys-apps/lm_sensors:sensord - Enable sensord - a daemon that can be used to periodically log sensor readings from hardware health-monitoring chips
sys-apps/memtest86+:serial - Compile with serial console support
sys-apps/memtest86:serial - Compile with serial console support
sys-apps/paludis:contrarius - Build the contrarius client, for building cross toolchains.
sys-apps/paludis:cran - Enable CRAN repository support.
sys-apps/paludis:glsa - Enable parsing of GLSA files
sys-apps/paludis:inquisitio - Enable inquisitio, the search client
sys-apps/paludis:pink - Use a less boring colourscheme than the default
sys-apps/paludis:portage - Enable experimental support for Portage configuration formats
sys-apps/paludis:qa - Enable QA tools.
sys-apps/paludis:zsh-completion - Enable zsh completion support
sys-apps/parted:device-mapper - Enable device-mapper support in parted
sys-apps/pciutils:network-cron - Monthly cronjob the update-pciids script
sys-apps/pcmcia-cs-modules:cardbus - Enable 32bit CardBus support
sys-apps/pcmcia-cs:trusted - Assume all users are trusted (Build unsafe user-space tools)
sys-apps/pcmcia-cs:xforms - Enable building the xforms based cardinfo binary
sys-apps/pcmciautils:staticsocket - Add support for static sockets
sys-apps/portage:epydoc - Generate api documentation with epydoc.
sys-apps/qingy:logrotate - Enable logrotate file installation
sys-apps/qingy:opensslcrypt - Encrypt communications between qingy and its GUI using OpenSSL
sys-apps/qtparted:jfs - Include JFS support
sys-apps/qtparted:ntfs - Include NTFS support
sys-apps/qtparted:reiserfs - Include ReiserFS support
sys-apps/qtparted:xfs - Include XFS support
sys-apps/shadow:nousuid - When nousuid is enabled only su from the shadow package will be installed with the setuid bit (mainly for single user systems)
sys-apps/suspend2-userui:fbsplash - Add support for framebuffer splash
sys-apps/tcng:tcsim - enable traffic simulator
sys-apps/tinylogin:make-symlinks - Create all the appropriate symlinks in /bin and /sbin
sys-apps/usbutils:network-cron - Monthly cronjob the update-usbids script
sys-apps/util-linux:old-crypt - build support for the older cryptoapi that earlier util-linux's included
sys-auth/pam_mysql:openssl - Use OpenSSL for md5 and sha1 support.
sys-auth/pam_pkcs11:pcsc-lite - build with pcsc-lite instead of openct
sys-block/gparted:fat - Include FAT16/FAT32 support
sys-block/gparted:hfs - Include HFS support
sys-block/gparted:jfs - Include JFS support
sys-block/gparted:ntfs - Include NTFS support
sys-block/gparted:reiser4 - Include ReiserFS4 support
sys-block/gparted:reiserfs - Include ReiserFS support
sys-block/gparted:xfs - Include XFS support
sys-block/partimage:nologin - Do not include login support
sys-block/scsiadd:suid - Install the binary suid, acknowledging the usual risks
sys-block/unieject:pmount - Make use of pmount wrapper and pmount-like permissions
sys-boot/arcboot:cobalt - Disables support for Cobalt Microserver hardware (Qube2/RaQ2)
sys-boot/arcboot:ip27 - Disables support for SGI Origin (IP27)
sys-boot/arcboot:ip28 - Disables support for SGI Indigo2 Impact R10000 (IP28)
sys-boot/arcboot:ip30 - Disables support for SGI Octane (IP30)
sys-boot/grub:custom-cflags - Enables custom cflags (not supported)
sys-boot/lilo:device-mapper - Enable device-mapper support
sys-boot/lilo:pxeserial - Avoid character echo on PXE serial console
sys-cluster/charm:cmkopt - Enable CMK optimisation
sys-cluster/charm:smp - Enable direct SMP support using shared memory
sys-cluster/charm:tcp - Use TCP (instead of UPD) for socket communication
sys-cluster/heartbeat:ldirectord - Adds support for ldiretord, use enabled because it has a lot of deps
sys-cluster/heartbeat:management - Adds support for management GUI.
sys-cluster/lam-mpi:pbs - Add support for PBS scheduling stuff
sys-cluster/lam-mpi:xmpi - Build support for the external XMPI debugging GUI
sys-cluster/mpich2:cxx - Add cxx headers
sys-cluster/mpich2:fast - Enabling fast turns off error checking and timing collection
sys-cluster/mpich2:mpe - Add mpe support
sys-cluster/mpich2:mpe-sdk - Include additional SDK support, jar files
sys-cluster/mpich2:romio - Enable romio, a high-performance portable MPI-IO implementation
sys-cluster/ocfs:aio - Add aio support
sys-cluster/openmpi:pbs - Add support for the Portable Batch System (PBS)
sys-cluster/torque:server - Enable compilation of server
sys-cluster/vzctl:logrotate - Enable logrotate file installation
sys-devel/binutils-hppa64:multislot - Allow for multiple versions of binutils to be emerged at once for same CTARGET
sys-devel/binutils-hppa64:multitarget - Adds support to binutils for cross compiling (does not work with gas)
sys-devel/binutils-nios2:multislot - Allow for multiple versions of binutils to be emerged at once for same CTARGET
sys-devel/binutils-nios2:multitarget - Adds support to binutils for cross compiling (does not work with gas)
sys-devel/binutils:multislot - Allow for multiple versions of binutils to be emerged at once for same CTARGET
sys-devel/binutils:multitarget - Adds support to binutils for cross compiling (does not work with gas)
sys-devel/gcc-nios2:multislot - Allow for SLOTs to include minor version (3.3.4 instead of just 3.3)
sys-devel/gcc:d - Enable support for the D programming language
sys-devel/gcc:ip28 - Enable building a compiler capable of building a kernel for SGI Indigo2 Impact R10000 (IP28)
sys-devel/gcc:ip32r10k - Enable building a compiler capable of building an experimental kernel for SGI O2 w/ R1x000 CPUs (IP32)
sys-devel/gcc:mudflap - Add support for mudflap, a pointer use checking library
sys-devel/gcc:multislot - Allow for SLOTs to include minor version (3.3.4 instead of just 3.3)
sys-devel/gcc:n32 - Enable n32 ABI support on mips
sys-devel/gcc:n64 - Enable n64 ABI support on mips
sys-devel/gcc:nopie - Disable PIE support (NOT FOR GENERAL USE)
sys-devel/gcc:nossp - Disable SSP support (NOT FOR GENERAL USE)
sys-devel/gcc:objc - Build support for the Objective C code language
sys-devel/gcc:objc++ - Build support for the Objective C++ language
sys-devel/gcc:objc-gc - Build support for the Objective C code language Garbage Collector
sys-devel/gcc:openmp - Build support for the OpenMP (support parallel computing)
sys-devel/kgcc64:multislot - Allow for SLOTs to include minor version (3.3.4 instead of just 3.3)
sys-devel/libperl:ithreads - Enable Perl threads, has some compatibility problems
sys-freebsd/freebsd-lib:atm - Enable Asynchronous Transfer Mode protocol support
sys-freebsd/freebsd-lib:gpib - Enable gpib support (TODO improve description)
sys-freebsd/freebsd-rescue:atm - Enable Asynchronous Transfer Mode protocol support
sys-freebsd/freebsd-sbin:atm - Enable Asynchronous Transfer Mode protocol support
sys-freebsd/freebsd-sbin:ipfilter - Enable ipfilter firewall support
sys-freebsd/freebsd-sbin:suid - Enable setuid root programs
sys-freebsd/freebsd-sbin:vinum - Enable vinum support (TODO improve description)
sys-freebsd/freebsd-share:isdn - Enable ISDN support
sys-freebsd/freebsd-ubin:atm - Enable Asynchronous Transfer Mode protocol support
sys-freebsd/freebsd-usbin:atm - Enable Asynchronous Transfer Mode protocol support
sys-freebsd/freebsd-usbin:ipfilter - Enable ipfilter firewall support
sys-freebsd/freebsd-usbin:ipsec - Enable IP Sec support
sys-freebsd/freebsd-usbin:isdn - Enable ISDN support
sys-freebsd/freebsd-usbin:nat - Enable Network Address Translation support
sys-freebsd/freebsd-usbin:suid - Enable setuid root programs
sys-fs/clvm:nocman - Allow users to build clvm without cman support and with gulm support
sys-fs/cryptsetup:dynamic - Build cryptsetup dynamically
sys-fs/cryptsetup-luks:dynamic - Build cryptsetup-luks dynamically
sys-fs/evms:hb - Enable support for heartbeat-1
sys-fs/evms:hb2 - Enable support for heartbeat-2
sys-fs/loop-aes:keyscrub - Protects the encryption key in memory but takes more cpu resources
sys-fs/loop-aes:padlock - Use VIA padlock instructions, detected at run time, code still works on non-padlock processors
sys-fs/lvm2:clvm - Allow users to build clustered lvm2
sys-fs/lvm2:cman - Cman support for clustered lvm
sys-fs/lvm2:gulm - Gulm support for clustered lvm
sys-fs/lvm2:nolvm1 - Allow users to build lvm2 without lvm1 support
sys-fs/lvm2:nolvmstatic - Allow users to build lvm2 dynamically
sys-fs/lvm2:nomirrors - Allow users to build lvm2 without mirror support
sys-fs/lvm2:nosnapshots - Allow users to build lvm2 without snapshot support
sys-fs/ntfs3g:suid - Install the binary SUID root, allowing users to mount ntfs-3g filesystems with potential security risks
sys-fs/ntfsprogs:fuse - Build a FUSE module
sys-fs/quota:rpc - Enable quota interaction via RPC
sys-fs/unionfs:nfs - Adds support for NFS file system
sys-kernel/ck-sources:ck-server - Tune the kernel for servers
sys-kernel/gentoo-sources:ultra1 - If you have a SUN Ultra 1 with a HME interface
sys-kernel/linux-docs:html - Install HTML documentation
sys-kernel/mips-headers:cobalt - Enables support for Cobalt Microserver hardware (Qube2/RaQ2)
sys-kernel/mips-headers:ip27 - Enables support for SGI Origin (IP27)
sys-kernel/mips-headers:ip28 - Enables support for SGI Indigo2 Impact R10000 (IP28)
sys-kernel/mips-headers:ip30 - Enables support for SGI Octane (IP30, 'Speedracer')
sys-kernel/mips-sources:cobalt - Enables support for Cobalt Microserver hardware (Qube2/RaQ2)
sys-kernel/mips-sources:ip27 - Enables support for SGI Origin (IP27)
sys-kernel/mips-sources:ip28 - Enables support for SGI Indigo2 Impact R10000 (IP28)
sys-kernel/mips-sources:ip30 - Enables support for SGI Octane (IP30, 'Speedracer')
sys-kernel/mips-sources:ip32r10k - Enables experimental support for IP32 R10K kernels (SGI O2, 'Moosehead')
sys-kernel/sparc-sources:ultra1 - If you have a SUN Ultra 1 with a HME interface
sys-libs/glibc:erandom - Enable erandom/frandom support in glibc for ssp
sys-libs/glibc:glibc-compat20 - Enable the glibc-compat addon.
sys-libs/glibc:glibc-omitfp - Configure glibc with --enable-omitfp which lets the build system determine when it is safe to use -fomit-frame-pointer
sys-libs/glibc: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.
sys-libs/glibc:nptlonly - Disables building the linuxthreads fallback in glibc ebuilds that support building both linuxthreads and nptl.
sys-libs/glibc:userlocales - build only the locales specified in /etc/locales.build
sys-libs/libuser:quotas - Enables support for user quotas
sys-libs/ncurses:trace - Enable test trace() support in ncurses calls
sys-libs/pam:audit - Enable support for sys-process/audit
sys-libs/pam:pam_chroot - Builds the pam_chroot module (enables per-user chroots at login)
sys-libs/pam:pam_console - Builds the pam_console module (enables per-user device permissions for console user)
sys-libs/pam:pam_timestamp - Builds the pam_timestamp module (enables recent successful attempt authentication)
sys-libs/pam:pwdb - If you want pam_pwdb.so installed to use pwdb as passwd db
sys-libs/uclibc:pregen - Use pregenerated locales
sys-libs/uclibc:savedconfig - Adds support to user defined configs
sys-libs/uclibc:uclibc-compat - build uclibc with backwards compatible options
sys-libs/uclibc:userlocales - build only the locales specified in /etc/locales.build
sys-libs/uclibc:wordexp - add support for word expansion (wordexp.h)
sys-power/acpid:logrotate - Use logrotate for rotating logs
sys-power/apcupsd:cgi - Add CGI script support
sys-power/apcupsd:lighttpd - Enable support for lighttpd
sys-power/cpufreqd:nforce2 - Enable for nforce2 voltage settings plug-in
sys-power/cpufreqd:nvidia - Enable nvidia overclocking (nvclock) plug-in
sys-power/cpufreqd:pmu - Enable Power Management Unit plug-in
sys-power/hibernate-script:logrotate - Use logrotate for rotating logs
sys-power/nut:cgi - Add CGI script support
sys-power/powersave:pam_console - Adds support for pam console from PAM
sys-power/suspend:fbsplash - Add support for framebuffer splash
sys-process/daemontools-scripts:withsamplescripts - Installs sample supervise scripts
sys-process/procps:n32 - Enable n32 ABI support on mips
www-apache/anyterm:opera - Enable workaround for bug in Opera web browser
www-apache/mod_ftpd:dbi - Enables libdbi support
www-apache/mod_log_sql:dbi - Enables libdbi support
www-apache/mod_mono:aspnet2 - Handle all applications using ASP.NET 2.0 engine by default
www-apache/mod_suphp:checkpath - Check if script resides in DOCUMENT_ROOT
www-apache/mod_suphp:mode-force - Run scripts with UID/GID specified in Apache configuration
www-apache/mod_suphp:mode-owner - Run scripts with owner UID/GID
www-apache/mod_suphp:mode-paranoid - Run scripts with owner UID/GID but also check if they match the UID/GID specified in the Apache configuration
www-apache/mod_vhs:suphp - Enable mod_suphp support
www-apache/pwauth:domain-aware - Ignore leading domain names in username (Windows compat)
www-apache/pwauth:faillog - Log failed login attempts
www-apache/pwauth:ignore-case - Ignore string case in username (mostly Windows compat)
www-apps/Embperl:modperl - Enable modperl support
www-apps/Embperl:xalan - Enable xalan support
www-apps/bugzilla:extras - optional Perl modules
www-apps/bugzilla:modperl - Enable modperl support
www-apps/egroupware:ical - Add ical support
www-apps/egroupware:jpgraph - Add jpgraph support
www-apps/gallery:raw - Add support for raw image formats
www-apps/gallery:netpbm - Add NetPBM support
www-apps/gallery:unzip - Add unzip support for the archive upload module
www-apps/gallery:zip - Add zip support for the zip download module
www-apps/horde-passwd:clearpasswd - Enables cleartext password storage in the vpopmail files
www-apps/knowledgetree:office - Allow to search in MSOffice documents
www-apps/knowledgetree:opendoc - Allow to search in opendoc documents
www-apps/knowledgetree:ps - Allow to search in postscript documents
www-apps/lxr:cvs - Adds support for indexing CVS
www-apps/lxr:freetext - Adds support for freetext search using swish-e
www-apps/mantisbt:bundled-adodb - use adodb bundled with web-application instead of system wide
www-apps/mediawiki:math - Adds math rendering support
www-apps/mediawiki:restrict - Initial setup will only allow sysop user to create new accounts, read and edit any pages
www-apps/moinmoin:rss - Add RSS support
www-apps/open-xchange:sieve - Install Smartsieve-OX
www-apps/open-xchange:webdav - Enable WebDav (Web-based Distributed Authoring and Versioning) support.
www-apps/rt:lighttpd - Add lighttpd support
www-apps/trac:cgi - Add CGI script support
www-apps/trac:enscript - Add enscript support to colourize code stored in the repository
www-apps/trac:silvercity - Add SilverCity support to colourize code stored in the repository
www-apps/viewcvs:cvsgraph - Add cvsgraph support to show graphical views of revisions and branches
www-apps/viewcvs:enscript - Add enscript support to colourize code stored in the repository
www-apps/viewcvs:mod_python - Add mod_python support
www-apps/viewcvs:standalone - Install the standalone client
www-apps/viewvc:cvs - Add cvs support
www-apps/viewvc:cvsgraph - Add cvsgraph support to show graphical views of revisions and branches
www-apps/viewvc:enscript - Add enscript support to colourize code stored in the repository
www-apps/viewvc:highlight - Add highlight support to colourize code stored in the repository
www-apps/viewvc:mod_python - Add mod_python support
www-apps/viewvc:subversion - Add subversion support
www-apps/websvn:enscript - Add enscript support to colourize code stored in the repository
www-client/elinks:bittorrent - Enable support for the BitTorrent protocol
www-client/elinks:finger - Enable support for the finger protocol
www-client/elinks:gopher - Enable support for the gopher protocol
www-client/kazehakase:hyperestraier - enable hyperestraier support for full-text search in history.
www-client/mozilla-firefox:filepicker - enable old gtkfilepicker from 1.0.x firefox
www-client/mozilla-firefox:mozdevelop - Enable features for web developers (e.g. Venkman)
www-client/mozilla-firefox:moznopango - Disable pango during runtime
www-client/mozilla-firefox:restrict-javascript - Pull in noscript extension to disable javascript globally, putting user fully in control of the sites he/she visits
www-client/mozilla-firefox:xforms - XForms is a standard to split up XHTML into XForms, instance data, and user interface
www-client/mozilla-firefox-bin:restrict-javascript - Pull in noscript extension to disable javascript globally, putting user fully in control of the sites he/she visits
www-client/opera:qt-static - Installs binaries statically linked to Qt
www-client/seamonkey:mozdevelop - Enable features for web developers (e.g. Venkman)
www-client/seamonkey:moznocompose - Disable building of mozilla's HTML editor component
www-client/seamonkey:moznoirc - Disable building of mozilla's IRC client
www-client/seamonkey:moznomail - Disable building mozilla's mail client
www-client/seamonkey:moznopango - Disable pango during runtime
www-client/seamonkey:moznoroaming - sroaming extension support
www-client/seamonkey:xforms - XForms is a standard to split up XHTML into XForms, instance data, and user interface
www-client/w3m:async - Enables asynchronous fetch
www-client/w3m:lynxkeymap - If you prefer Lynx-like key binding
www-misc/nsxml:xslt - Enables xslt support
www-servers/apache:mpm-event - (experimental) Event MPM - a variant of the worker MPM that tries to solve the keep alive problem - requires epoll support and kernel 2.6
www-servers/apache:mpm-itk - (experimental) Itk MPM - child processes have separate user/group ids
www-servers/apache:mpm-leader - (experimental) Leader MPM - leaders/followers variant of worker MPM
www-servers/apache:mpm-peruser - (experimental) Peruser MPM - child processes have separate user/group ids
www-servers/apache:mpm-prefork - Prefork MPM - non-threaded, forking MPM - similar manner to Apache 1.3
www-servers/apache:mpm-threadpool - (experimental) Threadpool MPM - keeps pool of idle threads to handle requests
www-servers/apache:mpm-worker - Worker MPM - hybrid multi-process multi-thread MPM
www-servers/apache:no-suexec - Don't install suexec with apache
www-servers/apache:static-modules - Build modules into apache instead of having them load at run time
www-servers/cherokee:coverpage - Installs the default cherokee coverpage
www-servers/fnord:auth - Enable HTTP authentication support
www-servers/lighttpd:memcache - Enable memcache support for mod_cml and mod_trigger_b4_dl
www-servers/lighttpd:rrdtool - Enable rrdtool support via mod_rrdtool
www-servers/lighttpd:webdav - Enables webdev properties
www-servers/lighttpd:xattr - if you want extended attributes enabled
www-servers/nginx:flv - Enables special processing module for flv files
www-servers/nginx:status - Enables stub_status module
www-servers/nginx:webdav - Enables webdav support
www-servers/ocsigen:logrotate - Install support files for logrotate
www-servers/ocsigen:ocamlduce - Enables ocamlduce XML typechecking for generated web pages
www-servers/pound:dynscaler - enable dynamic rescaling of back-end priorities
www-servers/pound:msdav - if you want the Microsoft DAV extensions enabled
www-servers/pound:unsafe - if you want the 'unsafe' characters passed through to the web servers
www-servers/resin:admin - Enable Resin admin webapp
www-servers/shttpd:cgi - Enable CGI script support
www-servers/shttpd:dmalloc - Enable debugging with the dmalloc library
www-servers/tomcat:admin - Enable Tomcat admin webapp
www-servers/tomcat:java5 - Use Java 1.5 source/target for compilation
x11-apps/xdpyinfo:dmx - Builds support for Distributed Multiheaded X
x11-base/kdrive:fbdev - Enables framebuffer kdrive server
x11-base/kdrive:font-server - Enables font server support
x11-base/kdrive:speedo - Enables Speedo font support
x11-base/kdrive:type1 - Enables Type1 font support
x11-base/xorg-server:dmx - Build the Distributed Multiheaded X server
x11-base/xorg-server:kdrive - Build the kdrive X servers
x11-base/xorg-server:xorg - Build the Xorg X server (HIGHLY RECOMMENDED)
x11-libs/cairo:glitz - Build with glitz support
x11-libs/cairo:opengl - When used along with USE=glitz, enables glitz-glx usage. Requires hardware opengl support
x11-libs/cairo:xcb - Support the X C-language Binding, a replacement for Xlib
x11-libs/fltk:noxft - Disables fltk; use for non-english characters
x11-libs/gtkmathview:t1lib - Enable t1lib support
x11-libs/libX11:xcb - Support the X C-language Binding, a replacement for Xlib (can break proprietary binaries, for example Sun Java)
x11-libs/libmatchbox:pango - Enable pango support
x11-libs/libmatchbox:xsettings - Enable the use of xsettings for settings management.
x11-libs/openmotif:xft - Build OpenMotif with support for XFT font renderer
x11-libs/qt:glib - Enable glib eventloop support
x11-libs/qt:immqt - Enable binary incompatible version of immodule for Qt
x11-libs/qt:immqt-bc - Enable binary compatible version of immodule for Qt
x11-libs/qt:pch - Enable precompiled header support for faster compilation times (gcc >3.4 only)
x11-libs/qt:qt3support - Enable the Qt3Support libraries for Qt4
x11-misc/adesklets:ctrlmenu - force CTRL to be pressed to fire context menu
x11-misc/adesklets:fontconfig - Support for managing custom fonts via fontconfig
x11-misc/dmenu:savedconfig - Add support to user defined configs
x11-misc/openclipart:gzip - Compresses clip art using gzip
x11-misc/vnc2swf:x11vnc - Install script that depends on x11vnc
x11-misc/xlockmore:xlockrc - Enables xlockrc for people without PAM
x11-misc/x11vnc:system-libvncserver - Build x11vnc against the system libvncserver (experimental)
x11-misc/xscreensaver:insecure-savers - Installs some screensaver modules as setuid root to enable cooler effects
x11-misc/xscreensaver:new-login - Enables users to create new logins even if the X screen is locked by someone else
x11-plugins/gkrellm-plugins:audacious - Install the audacious plugin
x11-plugins/gkrellmbups:nut - Enables monitoring Network-UPS (sys-power/nut)
x11-plugins/purple-plugin_pack:talkfilters - Enable support for app-text/talkfilters
x11-plugins/wmhdplop:gkrellm - Enable build of gkrellm module
x11-plugins/wmspaceclock:stlport - Enable support for STLport, greatly reducing CPU usage
x11-plugins/wmsysmon:high-ints - Enable support for monitoring 24 interrupts, useful on SMP machines
x11-terms/aterm:background - Enable background image support via libAfterImage
x11-terms/aterm:xgetdefault - Enable resources via X instead of aterm small version
x11-terms/eterm:escreen - enable built in screen support
x11-terms/eterm:etwin - enable twin support
x11-terms/hanterm:utempter - Records everytime a user logins in. Useful on multi-user systems.
x11-terms/mlterm:scim - Enable scim support
x11-terms/mlterm:uim - Enable uim support
x11-terms/mrxvt:menubar - Enable mrxvt menubar
x11-terms/mrxvt:utempter - Records everytime a user logins in. Useful on multi-user systems.
x11-terms/rxvt-unicode:iso14755 - Enable ISO-14755 support
x11-terms/rxvt:linuxkeys - Define LINUX_KEYS (changes Home/End key)
x11-terms/rxvt:xgetdefault - Enable resources via X instead of rxvt small version
x11-terms/xterm:paste64 - Enable support for bracketed paste mode
x11-terms/xterm:toolbar - Enable the xterm toolbar to be built.
x11-themes/redhat-artwork:audacious - Install Audacious theme
x11-themes/redhat-artwork:cursors - Install Bluecurve cursors
x11-themes/redhat-artwork:gdm - Install Bluecurve GDM theme
x11-themes/redhat-artwork:icons - Install Bluecurve icons
x11-themes/redhat-artwork:kdm - Install Bluecurve KDM theme
x11-themes/redhat-artwork:nautilus - Install Bluecurve Nautilus icons
x11-themes/skinenigmang-logos:dxr3 - install logos for lower osd color deep on dxr3 cards
x11-wm/beryl:emerald - Add support for one of the three decorators for Beryl
x11-wm/dwm:savedconfig - Add support to user defined configs
x11-wm/enlightenment:xrandr - Enable support for the X xrandr extension
x11-wm/fluxbox:disableslit - Disable the silt. Works around bug 122380.
x11-wm/fluxbox:disabletoolbar - Disable the toolbar.
x11-wm/fvwm:rplay - Enable rplay support
x11-wm/fvwm:stroke - Mouse Gesture support
x11-wm/ion3:ion3-voidupstreamsupport-truetype - Enable TrueType support, note this will *void* upstream support for your ion3 installation
x11-wm/matchbox-desktop:dnotify - Use the linux kernel directory notification feature.
x11-wm/matchbox-panel:dnotify - Use the linux kernel directory notification feature.
x11-wm/matchbox-panel:lowres - Optimize for low resolution screens.
x11-wm/sawfish:pango - Enable pango support
x11-wm/stumpwm-cvs:clisp - Use CLISP for the runtime
x11-wm/stumpwm-cvs:sbcl - Use SBCL for the runtime
x11-wm/vtwm:rplay - Enable rplay support, needed for sound.
x11-wm/windowmaker:modelock - Enable XKB language status lock support. README says: "If you don't know what it is you probably don't need it."
xfce-base/thunar:plugins - Enable trash panel plugin.
xfce-base/xfce4-extras:battery - Meta pulls in xfce4-battery dependency.
xfce-base/xfce4-extras:cpufreq - Meta pulls in xfce4-cpu-freq dependency.
xfce-extra/thunar-thumbnailers:grace - Enable .agr thumbnailers, grace support.
xfce-extra/thunar-thumbnailers:raw - Add support for raw image formats
xfce-extra/xfce4-sensors:hddtemp - Enable monitoring of disk temperatures (app-admin/hddtemp)