app-admin/collectd:collectd_plugins_ascent - Build the ascent input plugin (statistics about a free server for World of Warcraft)
app-admin/collectd:collectd_plugins_battery - Build the battery input plugin (charge, current and voltage of ACPI and PMU based laptop batteries)
app-admin/collectd:collectd_plugins_bind - Build the bind input plugin (name server and resolver statistics)
app-admin/collectd:collectd_plugins_conntrack - Build the conntrack input plugin (number of nf_conntrack entries)
app-admin/collectd:collectd_plugins_contextswitch - Build the contextswitch input plugin (number of context switches done by the operating system)
app-admin/collectd:collectd_plugins_cpu - Build the cpu input plugin (time spent in the system, user, nice, idle, and related states)
app-admin/collectd:collectd_plugins_cpufreq - Build the cpufreq input plugin (CPU frequency, for laptops with speedstep or similar)
app-admin/collectd:collectd_plugins_csv - Build the csv output plugin (write to comma separated values (CSV) files)
app-admin/collectd:collectd_plugins_curl - Build the curl input plugin (parse statistics from websites using regular expressions)
app-admin/collectd:collectd_plugins_curl_json - Build the curl_json input plugin (get json data via curl and parse it)
app-admin/collectd:collectd_plugins_curl_xml - Build the curl_xml input plugin (get xml data via curl and parse it)
app-admin/collectd:collectd_plugins_dbi - Build the dbi input plugin (execute SQL statements on databases and interpret the reply)
app-admin/collectd:collectd_plugins_df - Build the df input plugin (mountpoint usage)
app-admin/collectd:collectd_plugins_disk - Build the disk input plugin (sectors read/written, number of read/write actions, average completion time of IO-operations)
app-admin/collectd:collectd_plugins_dns - Build the dns input plugin (collects statistics of your DNS traffic on port udp/53)
app-admin/collectd:collectd_plugins_email - Build the email input plugin (opens a UNIX domain socket and starts accepting connections on that socket)
app-admin/collectd:collectd_plugins_entropy - Build the entropy input plugin (available entropy on a system)
app-admin/collectd:collectd_plugins_exec - Build the exec input/output plugin (executes scripts / applications and reads values back)
app-admin/collectd:collectd_plugins_filecount - Build the filecount input plugin (countd the number of files in a directory and all its subdirectories)
app-admin/collectd:collectd_plugins_fscache - Build the fscache input plugin (information about the caching infrastructure for network file-systems etc)
app-admin/collectd:collectd_plugins_gmond - Build the gmond input plugin (receive data from gmond, the client daemon of the Ganglia project)
app-admin/collectd:collectd_plugins_hddtemp - Build the hddtemp input plugin (temperature of hard disks)
app-admin/collectd:collectd_plugins_interface - Build the interface input plugin (information about traffic, packets and errors of interfaces)
app-admin/collectd:collectd_plugins_ipmi - Build the ipmi input plugin (read hardware sensors from servers using the Intelligent Platform Management Interface (IPMI))
app-admin/collectd:collectd_plugins_iptables - Build the iptables input plugin (statistics from a ip_tables based packet filter)
app-admin/collectd:collectd_plugins_irq - Build the irq input plugin (number of times each interrupt has been handled by the os)
app-admin/collectd:collectd_plugins_java - Build the java input plugin (embeds a JVM into collectd for writing plugins)
app-admin/collectd:collectd_plugins_libvirt - Build the libvirt input plugin (statistics about virtualized guests on a system)
app-admin/collectd:collectd_plugins_load - Build the load input plugin (system load)
app-admin/collectd:collectd_plugins_logfile - Build the logfile output plugin (writes log messages to a text file)
app-admin/collectd:collectd_plugins_madwifi - Build the madwifi input plugin (information about Atheros wireless LAN chipsets)
app-admin/collectd:collectd_plugins_match_empty_counter - Build the match_empty_counter filter plugin
app-admin/collectd:collectd_plugins_match_hashed - Build the match_hashed filter plugin
app-admin/collectd:collectd_plugins_match_regex - Build the match_regex filter plugin
app-admin/collectd:collectd_plugins_match_timediff - Build the match_timediff filter plugin
app-admin/collectd:collectd_plugins_match_value - Build the match_value filter plugin
app-admin/collectd:collectd_plugins_mbmon - Build the mbmon input plugin (information from mainboard sensors)
app-admin/collectd:collectd_plugins_memcachec - Build the memcachec input plugin (connects to a memcached server)
app-admin/collectd:collectd_plugins_memcached - Build the memcached input plugin (connects to a memcached daemon)
app-admin/collectd:collectd_plugins_memory - Build the memory input plugin (physical memory utilization)
app-admin/collectd:collectd_plugins_multimeter - Build the multimeter input plugin (reads a voltage or current from a multimeter connected to a serial bus)
app-admin/collectd:collectd_plugins_mysql - Build the mysql input plugin (connects to an MySQL-database and issues a SHOW STATUS command)
app-admin/collectd:collectd_plugins_netlink - Build the netlink input plugin (opens a netlink socket to the Linux kernel for getting statistics)
app-admin/collectd:collectd_plugins_network - Build the network input/output plugin (communicates with other instances of collectd)
app-admin/collectd:collectd_plugins_nfs - Build the nfs input plugin (usage of the Network File System)
app-admin/collectd:collectd_plugins_nginx - Build the nginx input plugin (number of requests handled by the nginx daemon)
app-admin/collectd:collectd_plugins_notify_desktop - Build the notify_desktop output plugin (uses libnotify to display notifications to the user)
app-admin/collectd:collectd_plugins_notify_email - Build the notify_email output plugin (uses libESMTP to send notifications to a configured email address)
app-admin/collectd:collectd_plugins_ntpd - Build the ntpd input plugin (queries an NTP server)
app-admin/collectd:collectd_plugins_tail - Build the tail input plugin (follows logfiles as e.g. tail -f)
app-admin/collectd:collectd_plugins_target_notification - Build the target_notification filter plugin
app-admin/collectd:collectd_plugins_target_replace - Build the target_replace filter plugin
app-admin/collectd:collectd_plugins_target_scale - Build the target_scale filter plugin
app-admin/collectd:collectd_plugins_target_set - Build the target_set filter plugin
app-admin/collectd:collectd_plugins_tcpconns - Build the tcpconns input plugin (number of TCP connections to or from a specified port)
app-admin/collectd:collectd_plugins_teamspeak2 - Build the teamspeak2 input plugin (collects traffic statistics from a teamspeak2 instance)
app-admin/collectd:collectd_plugins_ted - Build the ted input plugin (connects to The Energy Detective and reads the current power over connected power lines)
app-admin/collectd:collectd_plugins_thermal - Build the thermal input plugin (ACPI thermal zone information)
app-admin/collectd:collectd_plugins_tokyotyrant - Build the tokyotyrant input plugin (number of records and file size from a running Tokyo Tyrant server)
app-admin/collectd:collectd_plugins_unixsock - Build the unixsock output plugin (opens a UNIX domain socket and accepts connections)
app-admin/collectd:collectd_plugins_uptime - Build the uptime input plugin (system uptime)
app-admin/collectd:collectd_plugins_users - Build the users input plugin (number of users currently logged in)
app-admin/collectd:collectd_plugins_uuid - Build the uuid plugin (tries hard to determine the UUID of the system it is running on)
app-admin/collectd:collectd_plugins_varnish - Build the varnish input plugin
app-admin/collectd:collectd_plugins_vmem - Build the vmem input plugin (information about the virtual memory subsystem)
app-admin/collectd:collectd_plugins_vserver - Build the vserver input plugin (virtual servers running on a system)
app-admin/collectd:collectd_plugins_wireless - Build the wireless input plugin (signal quality, signal power and signal-to-noise ratio for wireless LAN cards)
app-admin/collectd:collectd_plugins_write_graphite - Build the write_graphite output plugin (sends the values collected by collectd to Carbon, the storage layer of the Graphite time-series database)
app-admin/ulogd:mysql - Build MYSQL output plugin to save packets in a mysql database.
app-admin/ulogd:pcap - Build PCAP output plugin to save packets in PCAP format. Uses the net-libs/libpcap library
app-admin/ulogd:postgres - Build PGSQL output plugin to save packets in a postgres database.
app-admin/ulogd:sqlite - Build SQLITE3 output plugin to save packets in an sqlite database.
app-admin/webalizer:xtended - Include the 404 extension
app-antivirus/clamav:clamdtop - A Top like tool which shows what clamd is currently scanning amongst other things
app-arch/cabextract:extra-tools - Install experimental tools: wince_info and wince_rename for examining and processing Windows CE installation cabinet header files; cabinfo for examining the structure of a cab file.
app-arch/cfv:bittorrent - Enable support for checking .torrent files
app-arch/dpkg:dselect - Build the dselect package-management frontend
app-arch/dump:ermt - encrypted rmt support
app-arch/file-roller:nautilus - Enable file-roller to integrate with gnome-base/nautilus by providing entries in its context menu
app-arch/file-roller:packagekit - Enable support for the distro-neutral package manager GUI app-admin/packagekit
app-arch/gzip:pic - disable optimized assembly code that is not PIC friendly
app-arch/libarchive:bzip2 - Allow accessing bzip2-compressed archives through libbz2 (which comes with app-arch/bzip2). This only affects libarchive's native support: bsdtar will keep using bunzip2 as a filter if that's not built-in.
app-arch/libarchive:zlib - Allow accessing gzip-compressed archives through sys-libs/zlib. This only affects libarchive's native support: bsdtar will keep using gunzip as a filter if that's not built-in. It's also needed for supporting extraction of ZIP files.
app-arch/p7zip:rar - Enable support for non-free rar decoder
app-arch/pbzip2:symlink - Install symlinks which override app-arch/bzip2 implementation
app-arch/rar:all_sfx - Install all SFX (Self-Extracting) files rather than just the native format (allows creation of Windows EXEs on Linux ELF systems)
app-crypt/ekeyd:minimal - Only install the ekey-egd-linux service rather than the full ekeyd package.
app-crypt/ekeyd:munin - Install a plugin for net-analyzer/munin to graph statistical data from ekeyd.
app-crypt/ekeyd:usb - Build the libusb-based userland daemon for accessing the EntropyKey (alternative to the CDC USB driver). It is suggested to use this option by default, as the CDC driver in the kernel often seems to be fragile (or the gadget implementation on the EntropyKey is too buggy), and can cause various problems.
app-crypt/kstart:afs - Enables afs support which means you can acquire an afs token and set PAGs. It's recommended to set this USE if you need authenticated access to an AFS cell for your daemon/app.
app-crypt/mit-krb5:doc - Creates and installs the API and implementation documentation. This is only useful if you want to develop software which depends on kerberos.
app-crypt/mit-krb5:keyutils - Enable for the keyring ccache using keyutils.
app-crypt/mit-krb5:openldap - Enable support for ldap as a database backend.
app-crypt/mit-krb5:pkinit - Enable pkinit support for the initial ticket.
app-crypt/ophcrack:tables - Require the additional tables used to carry out cracking (app-crypt/ophcrack-tables)
app-crypt/ophcrack-tables:vistafree - Installs the free Vista ophcrack tables
app-crypt/ophcrack-tables:xpfast - Installs the fast XP ophcrack tables
app-crypt/ophcrack-tables:xpsmall - Installs the small free XP ophcrack tables
app-crypt/seahorse:introspection - Use dev-libs/gobject-introspection for introspection
app-crypt/seahorse:ldap - Enable seahorse to manipulate GPG keys on a LDAP server.
app-crypt/seahorse-plugins:applet - Enable seahorse applet for gnome-base/gnome-panel
app-crypt/seahorse-plugins:gedit - Enable text encryption plugin to integrate into app-editors/gedit
app-crypt/seahorse-plugins:nautilus - Enable file encryption plugin to integrate into the gnome-base/nautilus context menu
app-editors/emacs:wide-int - Prefer wide Emacs integers (typically 62-bit). This option has an effect only on architectures where "long" and "long long" types have different size.
app-editors/emacs-vcs:toolkit-scroll-bars - Use the selected toolkit's scrollbars in preference to Emacs' own scrollbars
app-editors/emacs-vcs:wide-int - Prefer wide Emacs integers (typically 62-bit). This option has an effect only on architectures where "long" and "long long" types have different size.
app-editors/fe:sendmail - Send mail after editor abend
app-editors/gedit:introspection - Use dev-libs/gobject-introspection for introspection
app-editors/nano:debug - Enable debug messages and assert warnings. Note that these will all be sent straight to stderr rather than some logging facility.
app-editors/nano:justify - Enable justify/unjustify functions for text formatting.
app-editors/nano:minimal - Disable all fancy features, including ones that otherwise have a dedicated USE flag (such as spelling).
app-emulation/libvirt:iscsi - Allow using an iSCSI remote storage server as pool for disk image storage
app-emulation/libvirt:json - Support QEmu 0.13 JSON-based interface, using dev-libs/yajl.
app-emulation/libvirt:libvirtd - Builds the libvirtd daemon as well as the client utilities instead of just the client utilities
app-emulation/libvirt:lvm - Allow using the Logical Volume Manager (sys-apps/lvm2) as pool for disk image storage
app-emulation/libvirt:lxc - Support management of Linux Containers virtualisation (app-emulation/lxc)
app-emulation/libvirt:macvtap - Support for MAC-based TAP (macvlan/macvtap). For networking instead of the normal TUN/TAP. It has its advantages and disadvantages. macvtap support requires very new kernels and is currently evolving. Support for this is experimental at best.
app-emulation/libvirt:nfs - Allow using Network File System mounts as pool for disk image storage
app-emulation/libvirt:openvz - Support management of OpenVZ virtualisation (see sys-kernel/openvz-sources)
app-emulation/libvirt:parted - Allow using real disk partitions as pool for disk image storage, using sys-block/parted to create, resize and delete them.
app-emulation/libvirt:pcap - Support auto learning IP addreses for routing
app-emulation/libvirt:virt-network - Enable virtual networking (NAT) support for guests. Includes all the dependencies for NATed network mode. Effectively any network setup that relies on libvirt to setup and configure network interfaces on your host. This can include bridged and routed networks ONLY if you are allowing libvirt to create and manage the underlying devices for you. In some cases this requires enabling the 'netcf' USE flag (currently unavailable).
app-emulation/libvirt:virtualbox - Support management of VirtualBox virtualisation (one of app-emulation/virtualbox or app-emulation/virtualbox-ose)
app-emulation/libvirt:xen - Support management of Xen virtualisation (app-emulation/xen)
app-emulation/libvirt-glib:introspection - Use dev-libs/gobject-introspection for introspection
app-emulation/libvirt-glib:vala - Enable bindings for dev-lang/vala
app-emulation/lxc:vanilla - Avoid adding Gentoo Linux-specific modifications, which include the custom init script. This is present as a flag to avoid forcing dependencies over users that might not want have them around as they use LXC in contexts where the init script is not useful.
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/open-vm-tools:doc - Generate API documentation
app-emulation/open-vm-tools:fuse - Build vmblock-fuse in favor of FUSE based blocking mechanism for DnD
app-emulation/open-vm-tools:pic - Force shared libraries to be built as PIC
app-emulation/open-vm-tools:unity - Enable host unity support
app-emulation/qemu-kvm:mixemu - Enable audio mixer emulation. On Fedora, known to cause performance problems when using SDL output and ALSA. For OSS, locks the sound device from other applications.
app-emulation/qemu-kvm:tci - Enable the TCG Interpreter which can speed up or slowdown workloads depending on the host and guest CPUs being emulated. In the future it will be a runtime option but for now its compile time.
app-emulation/spice-vdagent:consolekit - Use sys-auth/consolekit to determine the master vdagentd in case of multiple running vdagentds (highly recommended)
app-emulation/uae:scsi - Enable the uaescsi.device
app-emulation/uae:sdl-sound - Use media-sound/sdl-sound for audio output
app-emulation/uae:ui - Build the user interface (could be gtk or ncurses based, depending on sdl, dga, svga and aalib USE flags)
app-emulation/vice:memmap - Enable extra monitor features
app-emulation/vice:xrandr - Enable support for the X xrandr extension
app-emulation/virt-manager:policykit - Enables sys-auth/polkit authentication support, required when using app-emulation/libvirt with PolicyKit authentication
app-emulation/virt-manager:sasl - Depend on the proper libraries needed to connect to SASL-enabled libvirtd instances (e.g. Kerberos-protected instances).
app-emulation/virt-manager:spice - Support connecting to SPICE-enabled virtual machines.
app-emulation/vmware-workstation:server - Install VMware Workstation Server component.
app-emulation/vmware-workstation:vix - Install VIX. The VIX API allows you to write programs and scripts that automate virtual machine operations, and run programs or manipulate files within guest operating systems.
app-office/abiword:grammar - Enable grammar checking via dev-libs/link-grammar
app-office/abiword:math - Enable support for x11-libs/gtkmathview
app-office/abiword:openxml - Enable OpenXML support
app-office/abiword:ots - Enable Text Summarizer plugin
app-office/abiword:plugins - Enable plugins build (see http://www.abisource.com/wiki/PluginMatrix for more information). If your file cannot be opened due lack of support, try enabling this.
app-office/abiword:thesaurus - Enable thesaurus support
app-office/abiword:wordperfect - Enable wordperfect file support via app-text/libwpd
app-office/libreoffice:xmlsec - Adds support for document signing using internal modified dev-libs/xmlsec and system dev-libs/nss
app-office/libreoffice-l10n:offlinehelp - Install help files locally instead of using the LibreOffice Wiki
app-office/lyx:aspell - Add support for aspell spellchecking
app-office/lyx:dia - Add support for diagrams (app-office/dia)
app-office/lyx:docbook - Add support for docbook export
app-office/lyx:dot - Add support for DOT import (media-gfx/graphviz)
app-office/lyx:enchant - Add support for enchant spellchecking wrapper (both aspell and hunspell can be used by LyX).
app-office/lyx:gnumeric - Add support for importing Gnumeric/OpenOffice/MS Excel spreadsheets into LyX.
app-office/lyx:html - Add support for HTML import
app-office/lyx:hunspell - Add support for spellchecking based on hunspell and reuse system-wide OpenOffice dictionaries. This also enable thesaurus dictionaries not accessible via aspell.
app-office/lyx:luatex - Add support for LuaTeX typesetting
app-office/lyx:monolithic-build - This should speed up compilation significantly when you have enough RAM (> 600 MB)
app-office/lyx:rcs - Add support for revision control via dev-vcs/rcs
app-office/lyx:rtf - Add support for RTF import/export packages
app-office/lyx:xetex - Add support for XeTeX typesetting
app-portage/eix:doc - Create description of the eix cache file additionally in html format
app-portage/eix:optimization - Accept upstream's choices for CXXFLAGS/LDFLAGS for optimization. Absense of this USE flag does not strip user's *FLAGS
app-portage/eix:security - This adds some checks which can prevent certain exploits if e.g. the eix code has a bug. If you use the hardened toolchain, using this flag does not increase security and can even lead to problems.
app-portage/eix:sqlite - Compile in support for portage's sqlite backend; to actually use it you need additional configuration of portage and eix
app-portage/eix:strong-optimization - Adds several more agressive CXXFLAGS/LDFLAGS for optimization like graphite (if available). May cause trouble with some buggy compiler versions. Absense of this USE flag does not strip user's *FLAGS
app-shells/bash:plugins - Add support for loading builtins 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/shish:diet - Use dev-libs/dietlibc
app-shells/tcsh:catalogs - Add support for NLS catalogs
app-text/cuneiform:graphicsmagick - Enables support of various input formats using media-gfx/graphicsmagick. Otherwise only uncompressed BMP files are supported.
app-text/cuneiform:imagemagick - Enables support of various input formats using media-gfx/imagemagick. Otherwise only uncompressed BMP files are supported.
app-text/dictd:judy - Build Judy-based (dev-libs/judy) plugin implementing fast "exact" and especially "lev" strategies
app-text/dictd:minimal - Don't build server but dict client, dictzip and dictfmt only.
app-text/docbook-sgml-utils:jadetex - Add support for app-text/jadetex (for processing tex files produced by the TeX backend of Jade)
app-text/stardict:pronounce - Install WyabdcRealPeopleTTS package (it is just many .wav files) to make StarDict pronounce English words
app-text/stardict:qqwry - Enable QQWry plugin, which provides information (in Chinese language) about geographical positions, owner, etc. for IP addresses
dev-cpp/xsd:ace - Enable support for serializing to/from an ACE CDR stream
dev-db/drizzle:curl - Enable the HTTP authentication plugin (using net-misc/curl). This is needed for the tests to apply properly.
dev-db/drizzle:doc - Build the API documentation for the package, using app-doc/doxygen. Warning, this might take over an hour on slower machines.
dev-db/drizzle:gearman - Enable the gearman plugins for user-defined functions and logging (using sys-cluster/gearman).
dev-db/drizzle:haildb - Use the dev-db/haildb libraries to replace the innodb plugin storage engine with haildb (an innodb fork).
dev-db/drizzle:md5 - Enable the MD5 plugin, using dev-libs/libgcrypt; this replaces the older openssl and gnutls USE flags.
dev-db/drizzle:memcache - Enable the memcache plugin for user-defined functions and statistics in I_S tables (using dev-libs/libmemcached). Currently restricts tests because of an upstream testsuite bug.
dev-db/drizzle:pam - Enable the PAM authentication plugin (using sys-libs/pam). The configuration file created will be /etc/pam.d/drizzle.
dev-db/firebird:client - Install client library and header files only
dev-db/firebird:superserver - Install SuperServer
dev-db/firebird:xinetd - Install ClassicServer
dev-db/haildb:debug - Enable extra debug codepaths and assertions. If disabled, both the debug code and assertions are removed from the resulting binaries. Optimisations are untouched.
dev-db/haildb:zlib - Add support for compressed tables through sys-libs/zlib.
dev-db/phpmyadmin:setup - Installs the phpMyAdmin setup utility. Users who don't use the utility should disable this USE flag for security reasons as the setup tool was the target of various exploits in the past.
dev-db/postgis:geos - Add the sci-libs/geos library for exact topological tests
dev-db/postgis:gtk - Build shp2pgsql-gui a graphical interface to shp2pgsql
dev-db/postgis:proj - Add the sci-libs/proj library for reprojection features
dev-db/postgresql-base:pg-intdatetime - Enable --enable-integer-datetimes configure option, which changes PG to use 64-bit integers for timestamp storage
dev-db/postgresql-base:pg_legacytimestamp - Use double precision floating-point numbers instead of 64-bit integers for timestamp storage.
dev-db/postgresql-server:pg_legacytimestamp - Use double precision floating-point numbers instead of 64-bit integers for timestamp storage.
dev-db/postgresql-server:uuid - Enable server side UUID generation (via dev-libs/ossp-uuid)
dev-db/sqlite:extensions - Enable support for dynamic loading of extensions
dev-db/sqlite:fts3 - Full text search using the fts3 module
dev-db/sqlite:secure-delete - Overwrite deleted information with zeros in addition to marking the space as available for reuse. This causes a performance penalty.
dev-db/sqlite:soundex - Enable the soundex function to compute soundex encodings of strings
dev-db/sqlite:threadsafe - Enable thread safe operation of sqlite
dev-db/sqlite:unlock-notify - Adds API for notifications when a database is unlocked in shared-cache mode
dev-db/unixODBC:minimal - Disable bundled drivers and extra libraries (most users don't need these)
dev-db/unixODBC:odbcmanual - Administrator, Internal Structure, Programmer and User documentation
dev-embedded/msp430-binutils:multislot - Allow for multiple versions of binutils to be emerged at once for same CTARGET
dev-embedded/msp430-binutils:multitarget - Adds support to binutils for cross compiling (does not work with gas)
dev-embedded/msp430-gcc:fixed-point - Enable fixed-point arithmetic support for MIPS targets in gcc (Warning: significantly increases compile time!)
dev-embedded/msp430-gcc:go - Build the GCC Go language frontend.
dev-embedded/msp430-gcc:graphite - Add support for the framework for loop optimizations based on a polyhedral intermediate representation
dev-embedded/msp430-gcc:libssp - Build SSP support into a dedicated library rather than use the code in the C library (DO NOT ENABLE THIS IF YOU DON'T KNOW WHAT IT DOES)
dev-embedded/msp430-gcc:mudflap - Add support for mudflap, a pointer use checking library
dev-embedded/msp430-gcc:multislot - Allow for SLOTs to include minor version (3.3.4 instead of just 3.3)
dev-embedded/msp430-gcc:objc - Build support for the Objective C code language
dev-embedded/msp430-gcc:objc++ - Build support for the Objective C++ language
dev-embedded/msp430-gcc:objc-gc - Build support for the Objective C code language Garbage Collector
dev-embedded/msp430-gdb:multitarget - Support all known targets in one gdb binary
dev-embedded/msp430-gdb:python - Enable support for the new internal scripting language, as well as extended pretty printers
dev-embedded/openocd:blaster - Enable support for Altera USE-Blaster
dev-embedded/openocd:dummy - Build the dummy port driver
dev-embedded/openocd:ftd2xx - Enable support for USB FTDI chips via dev-embedded/libftd2xx
dev-embedded/openocd:ftdi - Enable support for USB FTDI chips via dev-embedded/libftdi
dev-embedded/openocd:minidriver - Build the dummy minidriver
dev-embedded/openocd:parport - Enable support for parport JTAG devices
dev-embedded/openocd:presto - Enable support for AXIS PRESTO devices
dev-embedded/openocd:segger - Enable support for the Segger J-Link JTAG
dev-embedded/openocd:versaloon - Enable building support for the Versallon-lInk JTAG
dev-embedded/ponyprog:epiphany - Enable support for www-client/epiphany
dev-embedded/sdcc:boehm-gc - Enable Hans Boehm's garbage collector (dev-libs/boehm-gc)
dev-java/ecj-gcj:native - Build a native binary along with the jar. Provides faster execution time, but needs about 1G memory and some patience to compile.
dev-java/eclipse-ecj:ant - Support using ecj in Ant builds via dev-java/ant-eclipse-ecj
dev-java/emma:launcher - Install /usr/bin/emma. Collides with sci-biology/emboss.
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:alsa - Build with ALSA javax.sound.midi provider
dev-java/gnu-classpath:dssi - Build with DSSI javax.sound.midi provider
dev-java/gnu-classpath:gconf - Build with GConf preferences backend
dev-java/gnu-classpath:gjdoc - Build GJDoc, a documentation generator
dev-java/gnu-classpath:gmp - Build with GMP backend for java.math.BigInteger
dev-java/gnu-classpath:gstreamer - Build with GStreamer javax.sound.sampler provider
dev-java/gnu-classpath:gtk - Build with Gtk+ AWT peers
dev-java/gnu-classpath:qt4 - Build with Qt4 AWT peers
dev-java/gnu-classpath:xml - Build with native XML backend
dev-java/ibm-jdk-bin:javacomm - Enable Java Communications API support
dev-lang/python:threads - Enable threading support. (DON'T DISABLE THIS UNLESS YOU KNOW WHAT YOU'RE DOING)
dev-lang/python:wide-unicode - Enable wide Unicode implementation which uses 4-byte Unicode characters. Switching of this USE flag changes ABI of Python and requires reinstallation of many Python modules. (DON'T DISABLE THIS UNLESS YOU KNOW WHAT YOU'RE DOING)
dev-lang/python:wininst - Install Windows executables required to create an executable installer for MS Windows.
dev-lang/qu-prolog:pedro - Pedro subscription/notification communications system
dev-lang/ruby:libedit - Use the dev-libs/libedit library to provide the readline extension, used for instance by the irb tool. This flag will take precedence over the readline USE flag. If neither libedit nor readline USE flags are enabled, the readline extension will not be built (and irb will lose line editing functionality).
dev-lang/ruby:rdoc - Install dev-ruby/rdoc after installing Ruby.
dev-lang/ruby:readline - Use the sys-libs/readline library to provide the readline extension, used for instance by the irb tool. This flag is meaningful only if the libedit USE flag is disabled. If neither libedit nor readline USE flags are enabled, the readline extension will not be built (and irb will lose line editing functionality).
dev-lang/ruby:rubytests - Install ruby tests that can only be run after ruby is installed
dev-lang/ruby:yaml - Use the dev-libs/libyaml library to build the psych extension, available since Ruby 1.9.2_rc2, in alternative to the bundled syck-based parser.
dev-lang/ruby-enterprise:fastthreading - EXPERIMENTAL Enables fast threading routines. Removes support for callcc.
dev-lang/ruby-enterprise:libedit - Use the dev-libs/libedit library to provide the readline extension, used for instance by the irb tool. This flag will take precedence over the readline USE flag. If neither libedit nor readline USE flags are enabled, the readline extension will not be built (and irb will lose line editing functionality).
dev-lang/ruby-enterprise:readline - Use the sys-libs/readline library to provide the readline extension, used for instance by the irb tool. This flag is meaningful only if the libedit USE flag is disabled. If neither libedit nor readline USE flags are enabled, the readline extension will not be built (and irb will lose line editing functionality).
dev-lang/ruby-enterprise:rubytests - Install ruby tests that can only be run after ruby is installed
dev-lang/scala:binary - Install from (Gentoo-compiled) binary instead of building from sources. Set this when you run out of memory during build.
dev-lang/spidermonkey:threadsafe - Build a threadsafe version of spidermonkey
dev-libs/ferrisloki:stlport - Include support for dev-libs/STLport
dev-libs/folks:socialweb - Load web service contacts using net-libs/libsocialweb
dev-libs/folks:tracker - Load contacts from app-misc/tracker index
dev-libs/folks:utils - Build the folks-inspect utility
dev-libs/folks:vala - Regenerate pre-generated C code from Vala source
dev-libs/gdl:introspection - Use dev-libs/gobject-introspection for introspection
dev-libs/gecode:gist - Enable Gist, the Gecode Interactive Search Tool
dev-libs/geoip:perl-geoipupdate - Install pure perl version of geoipupdate, with Proxy Server support via via the "http_proxy" environment variable and easy to customize.
dev-libs/glib:systemtap - Build support for profiling and tracing using dev-util/systemtap
dev-libs/glib:utils - Install gtester-report utility to generate test report files for your software.
dev-libs/libburn:track-src-odirect - Read track input with O_DIRECT (see man 2 open), this may deliver a better write performance in some situations
dev-libs/libcdio:minimal - Only build the libcdio library and little more, just to be used to link against from multimedia players. With this USE flag enabled, none of the command-line utilities are built, nor is the CDDA library.
dev-libs/libcgroup:daemon - Install the configuration tools and init/config files.
dev-libs/libcgroup:tools - Install the cgroup rules processing daemon and init/config files.
dev-libs/libdbusmenu:introspection - Use dev-libs/gobject-introspection for introspection
dev-libs/libgdata:introspection - Use dev-libs/gobject-introspection for introspection
dev-libs/libgee:introspection - Use dev-libs/gobject-introspection for introspection
dev-libs/libisoburn:external-filters - Allow the use of external processes as file content filters (Note: this is a potential security risk)
dev-libs/libisoburn:external-filters-setuid - Also allow the use of external setuid processes as file content filters (Note: this is a potential security risk)
dev-libs/opensc:libtool - Use sys-devel/libtool for dynamically loading libraries rather than the host libdl/dlopen helpers.
dev-libs/opensc:openct - Use dev-libs/openct (and CT-API) for accessing Smartcard hardware. If neither openct nor pcsc-lite are enabled, only CT-API dynamic linking is enabled.
dev-libs/opensc:pcsc-lite - Use sys-apps/pcsc-lite (and PC/SC API) for accessing Smartcard hardware. If neither openct nor pcsc-lite are enabled, only CT-API dynamic linking is enabled.
dev-libs/udis86:pic - Force shared libraries to be built as PIC
dev-libs/xapian:brass - Enabled brass backend db support
dev-libs/xapian:chert - Enabled chert backend db support
dev-libs/xapian:flint - Enabled flint backend db support
dev-libs/xapian:inmemory - Enabled inmemory backend db support
dev-libs/xapian:remote - Enabled remot backend db support
dev-libs/xerces-c:iconv - Use iconv (virtual/libiconv) as message loader and transcoder (in general it would be possible to use iconv only as message loader and something else like icu or the native method as transcoder and vice-versa, but this is a less common case and hard to handle)
dev-libs/xerces-c:libwww - Use the net-libs/libwww library for fetching URLs, instead of the builtin method
dev-libs/xerces-c:threads - Enable threading support through pthread (or other libraries on AIX, IRIX, HPUX, Solars). Highly recommended
dev-libs/xml-security-c:nss - Use dev-libs/nss for certain crypto operations (configureable at runtime)
dev-libs/xml-security-c:xalan - Enable support for XSLT and XPath parsing by dev-libs/xalan-c
dev-libs/xmlrpc-c:abyss - Build the Abyss mini web-server.
dev-libs/xmlrpc-c:libxml2 - Use dev-libs/libxml2 to parse XML instead of the internal expat library.
dev-libs/xmlrpc-c:threads - Controls whether to build the Abyss web-server with pthreads or fork 'threading'.
dev-libs/xmlrpc-c:tools - Build the xmlrpc* tools.
dev-perl/Panotools-Script:gui - Installs GUIs for some tools
dev-perl/Sysadm-Install:hammer - Enable hammer() funtion to run a command in the shell and simulate a user hammering the ENTER key to accept defaults on prompts
dev-php/PEAR-HTTP_Download:minimal - Do not include support for PEAR-MIME_Type
dev-php/PEAR-HTTP_Download:postgres - Send postgres LOBs without buffering
dev-python/wxpython:doc - Install HTML wxWidgets docs and wxpython API reference.
dev-python/wxpython:examples - Install interactive demo module browser and sample applets.
dev-python/zsi:twisted - add support for dev-python/twisted
dev-ruby/barby:cairo - Add support for writing images (PNG, PS, EPS and, if supported, PDF and SVG) using dev-ruby/rcairo. Not available on JRuby.
dev-ruby/barby:datamatrix - Add support for datamatrix 2D codes using dev-ruby/semacode.
dev-ruby/barby:pdf-writer - Add support for writing PDF documents using dev-ruby/pdf-writer.
dev-ruby/barby:png - Add support for writing PNG images using dev-ruby/chunky_png.
dev-ruby/barby:prawn - Add support for writing PDF documents using dev-ruby/prawn.
dev-ruby/barby:qrcode - Add support for QRCode 2D codes using dev-ruby/rqrcode.
dev-ruby/barby:rmagick - Add support for writing images (among others PNG, GIF and JPEG) using dev-ruby/rmagick. Not available on JRuby.
dev-ruby/camping:mongrel - Also install www-servers/mongrel
dev-ruby/nokogiri:ffi - Use the Foreign Function Interface library (as provided by dev-java/jruby or dev-ruby/ffi depending on the implementation) rather than building a C extension to wrap around the libxml/libxslt interfaces. Note: JRuby always uses the FFI interface as native extensions are not supported.
dev-ruby/rails:asset-pipeline - Also install the default components for the asset pipeline. These are not required but they are activated automatically in new Rails projects by default.
dev-scheme/racket:places - Enable racket/place library for share-nothing parallelism and message-passing communication. Compared to futures, places are heavyweight, but they have a simpler performance model.
dev-scheme/racket:plot - Enable plot libraries
dev-scheme/racket:threads - Enable support for green threads
dev-scheme/scm:arrays - Support for arrays, uniform-arrays and uniform-vectors.
dev-scheme/scm:bignums - Support for large precision integers.
dev-scheme/scm:cautious - SCM will always check the number of arguments to interpreted closures.
dev-scheme/scm:dynamic-linking - Be able to load compiled files while running.
dev-scheme/scm:engineering-notation - Floats to display in engineering notation (exponents always multiples of 3) instead of scientific notation.
dev-scheme/scm:gsubr - generalized c arguments: for arbitrary (more then 11) arguments to C functions.
dev-scheme/scm:inexact - Support for floating point numbers.
dev-scheme/scm:ioext - Commonly available I/O extensions: line I/O, file positioning, file delete and rename, and directory functions.
dev-scheme/scm:macro - C level support for hygienic and referentially transparent macros (syntax-rules macros).
dev-util/geany-plugins:webkit - Enable webhelper plugin which requires net-libs/webkit-gtk
dev-util/glade:introspection - Use dev-libs/gobject-introspection for introspection
dev-util/global:vim - Integrate the GNU GLOBAL source code tag system with Vim
dev-util/google-perftools:debug - Build a set of libraries with debug support (so-called debugalloc). These are available by default but are not needed unless you're actually developing using tcmalloc.
dev-util/google-perftools:largepages - Use (experimental) larger pages for tcmalloc, this increases memory usage, but should speed up the allocation/free operations.
dev-util/google-perftools:minimal - Only build the tcmalloc_minimal library, ignoring the heap checker and the profilers.
dev-util/nvidia-cuda-toolkit:debugger - Installs the CUDA debugger.
dev-util/nvidia-cuda-toolkit:profiler - Installs the NVIDIA CUDA visual profiler.
dev-util/perf:demangle - Enable C++ symbol name demangling, using libbfd from sys-devel/binutils. When this flag is enabled, the package will have to be rebuilt after every version bump of binutils.
dev-util/perf:doc - Build documentation and man pages. With this USE flag disabled, the --help parameter for perf and its sub-tools will not be available. This is optional because it depends on a few documentation handling tools that are not always welcome on user systems.
dev-util/perf:perl - Add support for Perl as a scripting language for perf tools.
games-rpg/arx-libertatis:crash-reporter - Build a x11-libs/qt-gui-based tool that allows to submit crash information to the upstream backtracker.
games-rpg/arx-libertatis:debug - Enable asserts and debug logging.
games-rpg/arx-libertatis:demo - Install the Arx Fatalis demo data.
games-rpg/arx-libertatis:tools - Build tools that can extract the game's data and save files.
games-rpg/arx-libertatis:unity-build - Build everything in one big source file, allowing for faster build times and better optimizations at the cost of higher memory usage.
games-simulation/openttd:aplaymidi - Enables midi music in game, using aplaymidi as an external player
games-simulation/openttd:dedicated - Build only the openttd server, and not the client.
games-simulation/openttd:lzo - Enables LZO compression for savegames. This is only needed to load extremely old savegames. (versions before 0.2)
games-simulation/openttd:openmedia - Enables the free open media sets: OpenGFX, OpenSFX, OpenMSX, removing the requirement for proprietary TTD assets to play OpenTTD.
games-simulation/singularity:music - Install music files
games-strategy/x2:dynamic - Use dynamic binaries instead of static
games-strategy/x2:langpacks - Install additional language packs
games-strategy/x2:modkit - Install the modkit
games-util/gslist:web - Enable the web interface
games-util/pyfa:graph - Enable support for graphs
gnome-base/dconf:vala - Add support for dev-lang/vala
gnome-base/gconf:introspection - Use dev-libs/gobject-introspection for introspection
gnome-base/gconf:ldap - Build backend which enables default mail accounts, addressbooks and calendars for Evolution to be configured using each user's LDAP entry."
gnome-base/gconf:orbit - Use gnome-base/orbit for IPC, same as in gconf-2.x
gnome-base/gdm:consolekit - Allow proper handling of removable media according to who is actually present on the machine.
gnome-base/gdm:dmx - Enables Distributed Multihead X (DMX) support
gnustep-base/gnustep-make:libobjc2 - Enables use of the GNUstep Objective-C runtime (gnustep-base/libobjc2) with non-fragile ABI and sys-devel/clang compiler
gnustep-base/gnustep-make:native-exceptions - Enables use of the native Objective-C exception support (@try/@catch/@finally) built-in objective-c exceptions with compilers that support it
mail-client/claws-mail:ssl - Use gnutls for Secure Socket Layer transactions (deprecated, USE=gnutls should be used)
mail-client/evolution:clutter - Build with clutter support for animation effects
mail-client/evolution:connman - Enable net-misc/connman support (requires 'networkmanager' USE flag to be disabled).
mail-client/evolution:crypt - Enable GPG encryption support using app-crypt/gnupg and app-crypt/pinentry
mail-client/evolution:gnome-online-accounts - Enable using net-libs/gnome-online-accounts for authorization
mail-client/evolution:ldap - Enable support for fetching contacts from an LDAP or Active Directory server using net-nds/openldap
mail-client/evolution:map - Enable support for displaying contacts on a map inside evolution using media-libs/libchamplain
mail-client/evolution:networkmanager - Allows Evolution to automagically toggle online/offline mode by talking to net-misc/networkmanager and getting the current network state
mail-client/mail-notification:pop - Enable support for pop
mail-client/mail-notification:sylpheed - Enable support for MH mailboxes used by mail-client/sylpheed
mail-client/mutt:gpg - Enable support for app-crypt/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/mutt:tokyocabinet - Enable tokyocabinet database backend for header caching
mail-client/nail:kerberos - If network is enabled, this adds support for GSSAPI login on IMAP through virtual/kerberos.
mail-client/nail:net - Enable support for network protocols (POP, IMAP and SMTP). If you only need to send mail with the local Transport Agent, disabling this will get you support for only /usr/sbin/sendmail call.
mail-client/nail:ssl - If network is enabled, this adds support for S/MIME and SSL/TLS-powered protocols through dev-libs/openssl.
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-filter/mimedefang:poll - Use poll instead of select
mail-filter/opendkim:asyncdns - Use inbuilt asynchronous DNS library for queries
mail-filter/opendkim:ldap - Enable openldap as a dataset facilitator or keys, determining domains to sign for, and any other dataset that opendkim supports.
mail-filter/opendkim:lua - Enables control over signature verification, filtering and policy to be controlled by user defined lua scripts.
mail-filter/opendkim:opendbx - Use opendbx backend to facilitate dataset driven OpenDKIM configuration options like stats, bodylengthdb, etc. against a wide variety of database types
mail-filter/opendkim:poll - Use poll() instead of select() for the provided asynchronous resolver library.
mail-filter/opendkim:sasl - Used to authenticate to a LDAP server in various ways if required.
mail-filter/opendkim:unbound - Use the unbound dnssec library to perform DKIM DNS queries.
mail-filter/postgrey:targrey - Enables the targrey patch
mail-filter/qmail-scanner:spamassassin - Build faster mail-filter/spamassassin checks into qmail-scanner
mail-filter/spamassassin:qmail - Build qmail functionality and docs
mail-filter/spamassassin-fuzzyocr:amavis - Enable support for mail-filter/amavisd-new
mail-filter/spamassassin-fuzzyocr:gocr - Enable support for the gocr OCR engine
mail-filter/spamassassin-fuzzyocr:logrotate - Install support files for app-admin/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/spamdyke:tls - Enables TLS protocol for spamdyke
mail-filter/zdkimfilter:debug - Log process and signal information. Also leave the child process running for gdb examination.
mail-filter/zdkimfilter:mysql - MySQL client based statistics based storage.
mail-filter/zdkimfilter:opendbx - An alternate statistics based storage engine.
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/courier:web - Enable the web interface
mail-mta/courier:webmail - Enable the webmail interface
mail-mta/exim:dcc - Adds support for Distributed Checksum Clearinghouse (DCC)
mail-mta/exim:dkim - Adds support for DomainKeys Identified Mail (DKIM)
mail-mta/exim:dnsdb - Adds support for a DNS search for a record whose domain name is the supplied query
mail-mta/exim:dovecot-sasl - Adds support for Dovecot's authentication
mail-mta/exim:dsn - Adds support for Delivery Status Notifications (DSN)
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/msmtp:mta - Enable this to install as system-wide MTA
mail-mta/netqmail:authcram - Enable AUTHCRAM support
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
media-gfx/blender:redcode - This flag add support for RED CODE camera digital format (5K HD images *.r3d) - EXPERIMENTAL.
media-gfx/blender:tweak-mode - This flag allows you to model without confirming each translation, in particular it lets you grab with left mouse button (LMB) and not having to confirm by another click. Blender 'Tweak Mode' is similar to the 'Tweak Mode' of the Wings modeller (media-gfx/wings).
media-gfx/blender:verse - Adds verse clustering features to Blender.
media-gfx/brlcad:benchmarks - Run benchmarks during test phase (need test option enabled)
media-gfx/comix:rar - Pulls app-arch/unrar for rar file support
media-gfx/darktable:flickr - Add support for uploading photos to flickr
media-gfx/darktable:opencl - Enable opencl support
media-gfx/darktable:rawspeed - Enable the rawspeed backend
media-gfx/darktable:slideshow - Build the opengl slideshow viewer
media-gfx/digikam:addressbook - Add support for kdepim
media-gfx/digikam:linguas_ha - Hausa translation
media-gfx/digikam:linguas_mi - Maori translation
media-gfx/digikam:linguas_ven - Venda translation
media-gfx/digikam:themedesigner - Build the digikam theme designer
media-gfx/digikam:thumbnails - Enable thumbnails database support
media-gfx/digikam:video - Pull in mplayerthumbs to enable video thumbnails
media-gfx/enblend:gpu - GPU support for Enblend
media-gfx/enblend:image-cache - allow for processing of large images
media-gfx/eog:introspection - Use dev-libs/gobject-introspection for introspection
media-gfx/f-spot:flickr - Enable building of the Flickr exported.
media-gfx/fontforge:cjk - Controls whether fontforge understands the gb12345 encoding and installs cidmap package to edit CID-keyed fonts
media-gfx/fontforge:pango - Enable pango font rendering
media-gfx/fontforge:pasteafter - Controls whether fontforge has a paste after command (Useful for making words?). This is kind of fun, but it isn't useful for normal fonts.
media-gfx/fontforge:tilepath - Controls whether fontforge has a tile path command (a variant of expand stroke) This is useful for very decorative fonts, most people won't want it.
media-gfx/fontforge:truetype-debugger - Enable truetype debugger in fontforge
media-gfx/fontforge:type3 - Build in support for type3/svg fonts containing multilayered drawing with strokes, fills, images, etc. Type3 fonts are only supported by postscript printers (not by most windowing displays). They are capable of more exotic images than normal fonts but require much more effort to support.
media-gfx/fotowall:webcam - Enable webcam support
media-gfx/freewrl:glew - Enable glew extensions
media-gfx/freewrl:java - Build and install java EAI/SAI support library
media-gfx/freewrl:libeai - Build EAI C library
media-gfx/freewrl:osc - Allows for OSC-based control and communication between multiple freewrl instances
media-gfx/gimp:smp - Enable support for multiprocessors
media-gfx/gmic:graphicsmagick - Enable support for many common image file formats using the GraphicsMagick++ library
media-gfx/gmic:opencv - Enable support for webcams using the OpenCV library
media-gfx/graphicsmagick:fpx - Enable FlashPix support with media-libs/libfpx
media-gfx/graphicsmagick:modules - Compile graphicsmagick with dynamically loadable modules
media-gfx/graphicsmagick:q16 - Set storage quantum size to 16 (~2*memory)
media-gfx/graphicsmagick:q32 - Set storage quantum size to 32 (~5*memory)
media-libs/libcanberra:gstreamer - Enables gstreamer sound driver. Not useful when alsa or pulseaudio is available.
media-libs/libcanberra:gtk - Enables building of gtk+ helper library, gtk+ runtime sound effects and the canberra-gtk-play utility. To enable the gtk+ sound effects add canberra-gtk-module to the colon separated list of modules in the GTK_MODULES environment variable.
media-libs/libcanberra:gtk3 - Enables building of gtk+3 helper library, gtk+3 runtime sound effects and the canberra-gtk-play utility. To enable the gtk+3 sound effects add canberra-gtk-module to the colon separated list of modules in the GTK_MODULES environment variable.
media-libs/libcanberra:pulseaudio - Enables PulseAudio sound driver that should be able to support positional event sounds. This is the preferred choice for best sound events experience and picked by default if compiled in and possible to use at runtime.
media-libs/libcanberra:sound - Install x11-themes/sound-theme-freedesktop to get sounds on Gnome and Xfce.
media-libs/libcanberra:tdb - Enables Trivial Database support for caching purposes.
media-libs/libchamplain:html - Install gtk-doc html version for this package
media-libs/libchamplain:introspection - Use dev-libs/gobject-introspection for introspection
media-libs/libchamplain:vala - Generate bindings for dev-lang/vala
media-libs/libpostproc:3dnowext - Enable manually-optimised routines using the AMD 3DNow!Ex SIMD instruction set, present in modern AMD CPUs. (Check for 3dnowext in /proc/cpuinfo to know whether your CPU supports it).
media-libs/libpostproc:pic - Force shared libraries to be built as PIC (this is slower).
media-libs/libpostproc:vis - Adds support for SIMD optimizations for UltraSPARC processors.
media-libs/libquicktime:schroedinger - Enable Dirac video support (an advanced royalty-free video compression format) via libschroedinger (high-speed implementation in C of the Dirac codec)
media-libs/sdl-sound:physfs - Enable physfs support
media-libs/sge:image - enable sdl-image support
media-libs/silgraphite:pango - Enables the pango-graphite pango module.
media-libs/spandsp:fixed-point - Enable fixed point support
media-libs/spandsp:sse3 - Enable SSE3 support
media-libs/spandsp:sse4 - Enable SSE4 support
media-libs/spandsp:sse4a - Enable SSE4a support
media-libs/spandsp:sse5 - Enable SSE5 support
media-libs/svgalib:kernel-helper - Build the helper kernel module
media-libs/swfdec:alsa - Use ALSA for audio output
media-libs/swfdec:doc - Build documentation
media-libs/swfdec:ffmpeg - Use media-plugins/gst-plugins-ffmpeg to enable Flash video support. Necessary if you want to use sites like youtube
media-libs/swfdec:gstreamer - Enable media-libs/gstreamer to support various media input formats. i.e. audio (mp3) and video (flv)
media-libs/swfdec:gtk - Enable GTK+ convenience library while is necessary for all GTK+ apps using swfdec (gnome-extra/swfdec-gnome and www-plugins/swfdec-mozilla)
media-libs/swfdec:pulseaudio - Use media-sound/pulseaudio for audio output
media-libs/taglib:asf - Provide support for Microsoft's 'advanced systems format' media container.
media-libs/vips:fits - Enable support for the FITS image format through sci-libs/cfitsio
media-libs/vips:orc - Use dev-lang/orc for runtime optimisations
media-libs/win32codecs:real - Installs the real video codecs
media-libs/x264:10bit - Set output bit depth to 10, this may not be compatible with all decoders
media-libs/x264:interlaced - enable interlaced encoding support, this can decrease encoding speed by up to 2%
media-libs/x264:pic - disable optimized assembly code that is not PIC friendly
media-libs/xine-lib:dxr3 - Enable support for DXR3 mpeg acceleration cards.
media-libs/xine-lib:flac - Build the media-libs/flac based FLAC demuxer and decoder. This flag is not needed for playing FLAC content, neither standalone nor in Ogg container (OggFLAC), but might have better support for exotic features like 24-bit samples or 96kHz sample rates.
media-libs/xine-lib:fusion - Enable support for the Fusion audio sub system
media-libs/xine-lib:gtk - Build the gdkpixbuf-based image decoder plugin.
media-libs/xine-lib:imagemagick - Build the ImageMagick-based image decoder plugin.
media-libs/xine-lib:mad - Build the media-libs/libmad based mp3 decoder. This mp3 decoder has superior support compared to the one coming from FFmpeg that is used as a fallback. If you experience any bad behaviour with mp3 files (skipping, distorted sound) make sure you enabled this USE flag.
media-libs/xine-lib:mmap - Use mmap() function while reading file from local disks. Using mmap() will use more virtual memory space, but leaves to the Kernel the task of caching the file's data. mmap() access should be faster, but might misbehave if the device where the file resides in is removed during playback.
media-libs/xine-lib:real - Enable support for loading and using RealPlayer binary codecs on x86 and amd64 Linux. Enabling this USE flag might make the package non-redistributable in binary form.
media-libs/xine-lib:truetype - Use media-libs/freetype for font rendering and media-libs/fontconfig for font discovery. Enabling this USE flag will allow OSD (such as subtitles) to use more advanced font and to more easily select which font to use. The support for TrueType fonts in xine-lib is still experimental, and might not be as good looking as the bitmap fonts used with this USE flag disabled.
media-libs/xine-lib:vdpau - Enables VDPAU decoders (requires nVidia video cards to offload CPU processing to video card
media-libs/xine-lib:vdr - Build the VDR plugin
media-libs/xine-lib:vidix - Enable support for vidix video output.
media-libs/xine-lib:vis - Adds support for SIMD optimizations for UltraSPARC processors.
media-libs/xine-lib:win32codecs - Enable support for loading and using Windows 32-bit binary codecs on x86 Linux and FreeBSD. Enabling this USE flag might make the package non-redistributable in binary form.
media-libs/xine-lib:xvmc - Enable support for XVideo Motion Compensation (accelerated mpeg playback).
media-libs/xvid:pic - disable optimized assembly code that is not PIC friendly
media-plugins/audacious-plugins:adplug - Build with AdPlug (Adlib sound card emulation) support
media-plugins/kipi-plugins:vkontakte - Build plugin for vkontakte.ru
media-plugins/mediastreamer-ilbc:20ms-frames - enable 20ms frame size (default is 30ms). Some VOIP providers such as Gizmo5 (aka Sipphone) require the codec to be compiled with the 30ms setting.
media-plugins/vdr-graphtft:touchscreen - Enable Touchscreen support
media-plugins/vdr-music:4mb-mod - Enables support for modded FF-Card to 4MB ram or softdecoder
media-plugins/vdr-music:ff-card - Enables scrollmode on FF-Card
media-plugins/vdr-music:graphtft - Enable support for media-plugins/vdr-graphtft
media-plugins/vdr-music:hd - Support for HighDefinition OSD on softdecoder( e.g xineliboutput, vdpau, ehd )
media-plugins/vdr-pvr350:yaepg - Enables full support for the output format of media-plugins/vdr-yaepg
media-plugins/vdr-softdevice:mmxext - enables MMXExt support
media-plugins/vdr-streamdev:client - Compile the VDR plugin vdr-streamdev-client that acts like a dvb-budget card
media-plugins/vdr-streamdev:server - Compile the VDR plugin vdr-streamdev-server that allows remote systems to access the DVB cards used for the local VDR
media-plugins/vdr-xineliboutput:libextractor - Use media-libs/libextract to gather files' metadata in media-player
media-plugins/vdr-xineliboutput:vdpau - Enables VDPAU support (requires nVidia video cards) to offload MPEG2/MPEG4/VC1/WMV CPU processing to video card
media-plugins/vdr-xineliboutput:vdr - Compile the vdr output plugin to use local or remote xine as output
media-plugins/vdr-xineliboutput:xine - Compile the xine input plugin for displaying vdr video and OSD
media-radio/ax25-tools:X - Enable some X based configuration tools.
media-radio/fldigi:hamlib - Enables support by the Hamlib amateur radio rig control library to get/set frequency and mode of the ham radio in use
media-radio/tucnak2:ftdi - Enable support for FTDI USB chips
media-radio/tucnak2:hamlib - Enables support by the Hamlib amateur radio rig control library to get/set frequency and mode of the ham radio
media-radio/unixcw:ncurses - Enables building the curses based morse code tutor program 'cwcp'.
media-radio/xastir:festival - Enable text to speech synthesizer
media-radio/xastir:gdal - Support for some further map formats
media-radio/xastir:geotiff - Install geotiff support. Allows using USGS DRG topo maps or other types of geotiff mapes/images
media-radio/xastir:graphicsmagick - Use graphicsmagick instead imagemagick for rendering
media-sound/abcde:id3 - Support ID3, ID3v2 tagging of audio files
media-sound/abcde:normalize - Add support for normalizing audio file volume levels
media-sound/abcde:replaygain - Support for Replay Gain metadata, for relative volume adjustment
media-sound/abcm2ps:pango - Use the pango library to render fonts with non-latin characters
media-sound/alsaplayer:id3tag - Enables ID3 tagging with id3tag library
media-sound/amarok:daap - Enable the scripts for music sharing through DAAP. This flag adds dependencies on www-servers/mongrel to allow sharing of the Amarok music collection through DAAP protocol. Please note that turning this flag off has no effect on DAAP browsing.
media-sound/amarok:embedded - Use libmysqld, MySQL embedded server library. Try disabling this if you encounter -PIC related in amarok, it will make amarok rely only on standalone MySQL server.
media-sound/amarok:lastfm - Enable Last.fm streaming services support through media-libs/liblastfm
media-sound/puddletag:cover - Enables editing of FLAC cover art
media-sound/puddletag:musicbrainz - Enables support for musicbrainz, needs dev-python/python-musicbrainz
media-sound/puddletag:quodlibet - Enables support for editing media-sound/quodlibet databases
media-sound/pulseaudio:X - Build the X11 publish module to export PulseAudio information through X11 protocol for clients to make use. Don't enable this flag if you want to use a system wide instance. If unsure, enable this flag.
media-sound/pulseaudio:asyncns - Use libasyncns for asynchronous name resolution.
media-sound/pulseaudio:doc - Build the doxygen-described API documentation.
media-sound/pulseaudio:equalizer - Enable the equalizer module (requires sci-libs/fftw).
media-sound/pulseaudio:gdbm - Use sys-libs/gdbm to store PulseAudio databases. Recommended for desktop usage. This flag causes the whole package to be licensed under GPL-2 or later.
media-sound/pulseaudio:glib - Add support to dev-libs/glib-based mainloop for the libpulse client library, to allow using libpulse on glib-based programs.
media-sound/pulseaudio:gnome - Use GConf to store user preferences on streams and so on. Don't enable this flag if you want to use a system wide instance. If unsure, enable this flag.
media-sound/pulseaudio:orc - Use dev-lang/orc for runtime optimisations.
media-sound/pulseaudio:oss - Enable OSS sink/source (output/input). Deprecated, upstream does not support this on systems where other sink/source systems are available (i.e.: Linux). The padsp wrapper is now always build if the system supports OSS at all.
media-sound/pulseaudio:realtime - Makes PulseAudio use RealtimeKit (sys-auth/rtkit) to get real-time priority while running.
media-sound/pulseaudio:system-wide - Allow preparation and installation of the system-wide init script for PulseAudio. Since this support is only supported for embedded situations, do not enable without reading the upstream instructions at http://pulseaudio.org/wiki/WhatIsWrongWithSystemMode .
media-sound/pulseaudio:webrtc-aec - Uses the webrtc.org AudioProcessing library for enhancing VoIP calls greatly in applications that support it by performing acoustic echo cancellation, analog gain control, noise suppression and other processing.
media-sound/rezound:16bittmp - Use 16bit temporary files (default 32bit float), useful for slower computers
media-sound/rezound:soundtouch - compile with support for soundtouch
media-sound/rhythmbox:clutter - Build the visualizer plugin which uses media-libs/clutter and x11-libs/mx
media-sound/rhythmbox:daap - Build the local network music sharing plugin which uses the DAAP protocol using net-libs/libdmapsharing
media-sound/rhythmbox:dbus - Allow the im-status plugin to set the status of your IM clients using dev-python/dbus-python
media-sound/rhythmbox:html - Use net-libs/webkit-gtk for detecting and displaying HTML podcast episode descriptions.
media-sound/rhythmbox:lastfm - Build a plugin for Last.fm and Librefm scrobbling
media-sound/rhythmbox:udev - Enable hardware detection via sys-fs/udev replacing the deprecated sys-apps/hal code
media-sound/rhythmbox:upnp - Build a plugin for local network music sharing which uses UPnP protocols using media-video/coherence, dev-python/louie, and dev-python/twisted
media-sound/xnoise:lyrics - Enable support for lyrics fetching
media-sound/xwax:alsa - Adds support for ALSA audio input/output.
media-sound/xwax:cdda - Sets runtime dependencies to support decoding audio from a compact disc.
media-sound/xwax:fallback - Sets runtime dependencies to support decoding "other" audio files.
media-sound/xwax:mp3 - Sets runtime dependencies to support decoding MP3 audio.
media-sound/xwax:xwax_decoders_aac - Sets runtime dependencies to support decoding AAC audio.
media-sound/xwax:xwax_decoders_cd - Sets runtime dependencies to support decoding audio from a compact disc.
media-sound/xwax:xwax_decoders_flac - Sets runtime dependencies to support decoding FLAC audio.
media-sound/xwax:xwax_decoders_misc - Sets runtime dependencies to support decoding "other" audio files.
media-sound/xwax:xwax_decoders_mp3 - Sets runtime dependencies to support decoding MP3 audio.
media-sound/xwax:xwax_decoders_ogg - Sets runtime dependencies to support decoding Ogg Vorbis audio.
media-tv/freevo:ivtv - Enables ivtv support
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/freevo:tvtime - Enables tvtime support, additional to tv use flag
media-tv/gentoo-vdr-scripts:nvram - Add support for using nvram-wakeup to set wakeup time in bios
media-tv/mythtv:alsa - Allows MythTV to directly output sound to ALSA devices, this is needed if you are using ALSA dmix or SPDIF. Note, you will have to physically type your device into the MythTV configuration since it will only give you /dev/dsp devices in the drop down.
media-tv/mythtv:altivec - Builds ffmpeg's codec libraries with altivec support.
media-tv/mythtv:autostart - Uses a custom autostart configuration gleaned from experience with MythTV since its early versions and discussed with other MythTV maintainers and users. Does not rely on KDE being installed like most methods do.
media-tv/mythtv:cec - Allows you to control CEC enabled TVs via HDMI. Currently requires a USB based CEC -> HDMI injector between your TV and video card since no graphics drivers support CEC natively.
media-tv/mythtv:crystalhd - Allows you to utilize a Broadcom CrystalHD hardware based video decoder to improve the performance of video decode.
media-tv/mythtv:debug - Instructs Qt to use the 'debug' target instead of 'release' target. If your MythTV is crashing or you need a backtrace, you need to compile it with this option otherwise the debugging data is useless.
media-tv/mythtv:dvb - Enables support for Linux DVB cards. These include all cards that work with digital signals such as ATSC, DVB-T, DVB-C, and DVB-S, QAM-64, and QAM-256.
media-tv/mythtv:ieee1394 - Allows MythTV to communicate and use Firewire enabled Cable boxes. These are typically found in the United States, where such support is required by law. This will also install Firewire test programs and external channel changers if the internal changer does not work.
media-tv/mythtv:jack - Allows MythTV to use JACK as your sound output device. You will have to manually configure the path to your JACK settings.
media-tv/mythtv:lcd - Tells MythTV that you have an instance of app-misc/lcdproc configured on your machine and it should output information such as current time, show name, episode name, etc to that LCD.
media-video/aravis:X - Build the GTK+-based video viewer for aravis. This requires GStreamer and a few plugins but technically not the GST plugin for aravis.
media-video/aravis:gstreamer - Build the GStreamer plugin for aravis, but not the video viewer.
media-video/dvdauthor:graphicsmagick - Use media-gfx/graphicsmagick instead of media-gfx/imagemagick
media-video/dvdrip:fping - Enables fping support for cluster rendering
media-video/dvdrip:subtitles - Enables support for subtitle ripping
media-video/ffmpeg:3dnowext - Enable manually-optimised routines using the AMD 3DNow!Ex SIMD instruction set, present in modern AMD CPUs. (Check for 3dnowext in /proc/cpuinfo to know whether your CPU supports it).
media-video/ffmpeg:aacplus - AAC+ encoding via media-libs/libaacplus.
media-video/ffmpeg:amr - Enables Adaptive Multi-Rate Audio support
media-video/ffmpeg:avresample - Enables libavresample, media-video/libav version of libswresample (which installed and makes libavresample redundant): A conversion library between uncompressed audio formats.
media-video/ffmpeg:pic - Force shared libraries to be built as PIC (this is slower)
media-video/ffmpeg:rtmp - Enable Real Time Messaging Protocol using librtmp
media-video/ffmpeg:schroedinger - Enable Dirac video support (an advanced royalty-free video compression format) via libschroedinger (high-speed implementation in C of the Dirac codec).
media-video/ffmpeg:vaapi - Enables VAAPI (Video Acceleration API) for hardware decoding
media-video/ffmpeg:vdpau - Enables VDPAU decoders (requires nVidia video cards and binary nvidia-drivers to offload CPU processing to video card)
media-video/ffmpeg:vis - Adds support for SIMD optimizations for UltraSPARC processors.
media-video/ffmpeg:vpx - Enables vp8 codec support using libvpx: Decoding vp8 does not require this to be enabled but libvpx can also be used for decoding; encoding vp8 requires this useflag to be enabled though.
media-video/ffmpeg2theora:kate - Adds support for Ogg Kate subtitles via libkate.
media-video/gnome-mplayer:dconf - Enable support for gnome-base/dconf
media-video/google2srt:html - Install HTML documentation
media-video/griffith:csv - Enable proper support for csv import (respectively auto-detection encoding of csv files)
media-video/h264enc:ogm - Support for OGM container format
media-video/hwdecode-demos:vaapi - Enables VAAPI (Video Acceleration API) for hardware decoding
media-video/hwdecode-demos:vdpau - Enables VDPAU decoders (requires nVidia video cards to offload CPU processing to video card
media-video/kino:gpac - Enable GPAC support when exporting to 3GPP format
media-video/kmplayer:npp - Compile the npp backend that plays xembed style browser plugins.
media-video/libav:3dnowext - Enable manually-optimised routines using the AMD 3DNow!Ex SIMD instruction set, present in modern AMD CPUs. (Check for 3dnowext in /proc/cpuinfo to know whether your CPU supports it).
media-video/libav:aac - Use external vo-aacenc library for AAC encoding
media-video/libav:amr - Enable Adaptive Multi-Rate Audio support
media-video/libav:avx - Adds support for Advanced Vector Extensions instructions (Intel Sandy Bridge, AMD Bulldozer and later chips)
media-video/libav:cdio - Enable audio CD grabbing with dev-libs/libcdio.
media-video/libav:cpudetection - Enables runtime CPU detection (useful for bindist, compatibility on other CPUs).
media-video/libav:dirac - Enable Dirac video support (an advanced royalty-free video compression format) via the reference library: dirac.
media-video/libav:openssl - Prefer dev-libs/openssl over net-libs/gnutls to provide SSL/TLS support (notice: the resulting binaries are unredistributable).
media-video/libav:pic - Force shared libraries to be built as PIC (this is slower).
media-video/libav:qt-faststart - Build and install qt-faststart application.
media-video/libav:rtmp - Enable Real Time Messaging Protocol using librtmp instead the native implementation.
media-video/libav:schroedinger - Enable Dirac video support (an advanced royalty-free video compression format) via libschroedinger (high-speed implementation in C of the Dirac codec).
media-video/libav:ssl - Enable SSL/TLS support using dev-libs/openssl or dev-libs/gnutls.
media-video/libav:ssse3 - faster floating point optimization for SSSE3 capable chips (Intel Core 2 and later chips).
media-video/mplayer:rtc - Enables usage of the linux real time clock. The alternative is software emulation of rtc
media-video/mplayer:rtmp - Enables RTMPDump Streaming Media support
media-video/mplayer:schroedinger - Enable Dirac video support (an advanced royalty-free video compression format) via libschroedinger (high-speed implementation in C of the Dirac codec).
media-video/mplayer:shm - Enable support for shm
media-video/mplayer:ssse3 - faster floating point optimization for SSSE3 capable chips (Intel Core 2 and later chips)
media-video/mplayer:tga - Enables Targa video output
media-video/mplayer:vdpau - Enables experimental VDPAU support (requires nVidia video cards) to offload MPEG2/MPEG4/VC1/WMV CPU processing to video card
media-video/mplayer:vidix - Support for vidix video output
media-video/mplayer:vpx - Enables vp8 codec support using libvpx: Decoding vp8 does not require this to be enabled but libvpx can also be used for decoding; encoding vp8 requires this useflag to be enabled though.
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/mplayer2:3dnowext - Enable 3dnowext cpu instructions
media-video/mplayer2:bl - Blinkenlights video output
media-video/mplayer2:bluray - Enable playback of Blu-ray filesystems
media-video/mplayer2:real - Adds real audo/video support
media-video/mplayer2:rtc - Enables usage of the linux real time clock. The alternative is software emulation of rtc
media-video/mplayer2:shm - Enable support for shm
media-video/mplayer2:ssse3 - Faster floating point optimization for SSSE3 capable chips (Intel Core 2 and later chips)
media-video/mplayer2:symlink - Copy all binaries and configuration into locations occupied by media-video/mplayer and thus act like drop-in replacement.
media-video/mplayer2:tga - Enables Targa video output
media-video/mplayer2:vdpau - Enables experimental VDPAU support (requires nVidia video cards) to offload MPEG2/MPEG4/VC1/WMV CPU processing to video card
media-video/mplayer2:xanim - Enables support for xanim based codecs
media-video/ogmrip:ogm - Support for OGM container format
media-video/ogmrip:srt - Support for SRT subtitle format
media-video/rtmpdump:gnutls - Use GnuTLS library instead of the default OpenSSL
media-video/rtmpdump:polarssl - Use PolarSSL library instead of the default OpenSSL
media-video/vlc:libv4l2 - Enables Libv4l2 Video4Linux2 support (for conversion from various video formats to standard ones, needed to use v4l2 devices with strange formats).
media-video/vlc:linsys - Enables support for Linux Linear Systems Ltd. SDI and HD-SDI input cards.
media-video/vlc:live - Enables live555 streaming media support (client support for rtsp).
media-video/vlc:macosx - Enables Mac OS X gui support.
media-video/vlc:macosx-audio - Enables Mac OS X audio module.
media-video/vlc:macosx-dialog-provider - Enables Mac OS X dialog module.
media-video/vlc:macosx-eyetv - Enables Mac OS X EyeTV (TNT Tuner) module.
media-video/vlc:macosx-qtkit - Enables Mac OS X qtkit module: qtcapture (video) and qtsound (audio) module.
media-video/vlc:macosx-quartztext - Enables Mac OS X quartz text module.
media-video/vlc:macosx-vout - Enables Mac OS X video output module.
media-video/vlc:matroska - Enables matroska support using reference libraries (fallback on other existing matroska support if disabled, i.e., matroska enabled FFmpeg)
media-video/vlc:media-library - Build the (sqlite based) media library.
media-video/vlc:qt4 - Builds a x11-libs/qt based frontend. It is now the most up-to-date graphical interface available.
media-video/vlc:remoteosd - Enables RemoteOSD plugin (VNC client as video filter).
media-video/vlc:rtsp - Enables real audio and RTSP modules.
media-video/vlc:run-as-root - Allows vlc to start for root. Don't enable this unless you have a very specific (e.g. embedded) need for it!
media-video/vlc:schroedinger - Enable Dirac video support (an advanced royalty-free video compression format) via libschroedinger (high-speed implementation in C of the Dirac codec).
media-video/vlc:sdl-image - Enables sdl image video decoder (depends on sdl)
media-video/vlc:shine - Enables shine fixed point mp3 encoder.
media-video/vlc:shout - Enables libshout output.
media-video/vlc:sid - Adds support for playing C64 SID files through media-libs/libsidplay-2.
media-video/vlc:skins - Enables support for the skins2 interface.
media-video/vlc:stream - Enables sout module for audio/video data streaming/transcoding/etc..
media-video/vlc:switcher - Enables MPEG2 video switcher stream output module.
media-video/vlc:swscale - Enables image scaling and conversion via libswscale (part of FFmpeg).
media-video/vlc:twolame - Enables twolame support (MPEG Audio Layer 2 encoder).
media-video/vlc:upnp - Enables support for Intel UPnP stack.
media-video/vlc:vaapi - Enables VAAPI (Video Acceleration API) for hardware decoding
media-video/vlc:vcdx - Enables VCD with navigation via libvcdinfo (depends on cdio)
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.
net-analyzer/munin:asterisk - Install the packages required for monitoring Asterisk. Disabling the flag does not remove any plugin files.
net-analyzer/munin:cgi - Install the CGI-compatible scripts for on-the-fly generation of web pages and graphs. This is only meaningful if the minimal USE flag is disabled.
net-analyzer/munin:http - Install dev-perl/libwww-perl required for monitoring HTTP-based services such as Apache and nginx. Disabling the flag does not remove any plugin file.
net-analyzer/munin:ipv6 - Add support for IPv6 in munin-node. IPv6 support for the master is always enabled, but the node requires a newer version of dev-perl/net-server, capable of listening to IPv6 sockets.
net-analyzer/munin:syslog - Configure the node by default to log on syslog. This requires the presence of virtual/perl-Sys-Syslog. As of version 2.0.2, the master scripts only log to file, and not to syslog.
net-analyzer/nagios-nsca:crypt - Build support for crypted communication with nsca, through dev-libs/mcrypt. It's recommended not to disable this flag unless all the communication will be handled in an absolutely safe environment.
net-analyzer/nagios-plugins:jabber - Install the script for sending IM notifications over Jabber with Nagios.
net-analyzer/nagios-plugins:nagios-dns - Install net-dns/bind-tools required for monitoring DNS servers. Disabling the flag does not remove any plugin file.
net-analyzer/nagios-plugins:nagios-game - Install games-util/qstat required for monitoring FPS servers. Disabling the flag does not remove any plugin file.
net-analyzer/nagios-plugins:nagios-ntp - Install net-misc/ntp required for monitoring NTP servers and drifts. Disabling the flag does not remove any plugin file.
net-analyzer/nagios-plugins:nagios-ping - Install net-analyzer/fping required for fancy ping monitoring. Disabling the flag does not remove any plugin file.
net-analyzer/nagios-plugins:nagios-ssh - Install net-misc/openssh required for monitoring SSH servers. Disabling the flag does not remove any plugin file.
net-analyzer/nagios-plugins:ups - Install sys-power/nut required for monitoring compatible UPS units. Disabling the flag does not remove any plugin file.
net-analyzer/pchar:pcap - Use the net-libs/libpcap library
net-analyzer/pmacct:64bit - Use 64bit counters instead of 32bit ones
net-analyzer/pmacct:ulog - Enable ULOG support
net-analyzer/rrdcollect:exec - Enable exec:/// support
net-analyzer/rrdcollect:librrd - Use the librrd library from net-analyzer/rrdtool
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 net-libs/libnids for packet capturing
net-analyzer/scanlogd:pcap - Use net-libs/libpcap for packet capturing
net-analyzer/scapy:pyx - Enable dev-python/pyx support for psdump/pdfdump commands
net-analyzer/scapy:tcpreplay - Enable net-analyzer/tcpreply support for fast packet replay
net-analyzer/scapy:visual - Enable dev-python/visual support for 3d graphs
net-analyzer/smokeping:speedy - Use dev-perl/SpeedyCGI instead of perl to speed up cgi scripts
net-analyzer/snort:active-response - Enables support for automatically sending TCP resets and ICMP unreachable messages to terminate connections. Used with inline deployments.
net-analyzer/snort:aruba - Adds support for monitoring wireless traffic using a Aruba Mobility Controler.
net-analyzer/snort:decoder-preprocessor-rules - Added support to provide action control (alert, drop, pass, etc) over preprocessor and decoder generated events.
net-analyzer/snort:dynamicplugin - Enable ability to dynamically load preprocessors, detection engine, and rules library. This is required if you want to use shared object (SO) snort rules.
net-analyzer/snort:flexresp3 - Enables support for new flexable response preprocessor for enabling connection tearing for inline deployments. Replaces flexresp and flexresp2.
net-analyzer/snort:gre - Enable support for inspecting and processing Generic Routing Encapsulation (GRE) packet headders. Only needed if you are monitoring GRE tunnels.
net-analyzer/snort:inline-init-failopen - Enables support to allow traffic to pass (fail-open) through inline deployments while snort is starting and not ready to begin inspecting traffic. If this option is not enabled, network traffic will not pass (fail-closed) until snort has fully started and is ready to perform packet inspection.
net-analyzer/snort:large-pcap-64bit - Allows Snort to read pcap files that are larger than 2 GB. ONLY VALID FOR 64bit SYSTEMS!
net-analyzer/snort:linux-smp-stats - Enable accurate statistics reporting through /proc on systems with multipule processors.
net-analyzer/snort:mpls - Enables support for processing and inspecting Multiprotocol Label Switching MPLS network network traffic. Only needed if you are monitoring an MPLS network.
net-analyzer/snort:normalizer - Enables support for normalizing packets in inline deployments to help minimize the chances of detection evasion.
net-analyzer/snort:paf - Enables support for Protocol Aware Flushing. This allows Snort to statefully scan a stream and reassemble a complete protocol data unit regardless of segmentation.
net-analyzer/snort:perfprofiling - Enables support for preprocessor and rule performance profiling using the perfmonitor preprocessor.
net-analyzer/snort:ppm - Enables support for setting per rule or per packet latency limits. Helps protect against introducing network latency with inline deployments.
net-analyzer/snort:react - Enables support for the react rule keyword. Supports interception, termination, and redirection of HTTP connections.
net-analyzer/snort:reload-error-restart - Enables support for completely restarting snort if an error is detected durring a reload.
net-analyzer/snort:targetbased - Enables support in snort for using a host attibute XML file (attribute_table.dtd). This file needs to be created by the user and should define the IP address, operating system, and services for all hosts on the monitored network. This is cumbersome, but can improve intrusion detection accuracy.
net-analyzer/snort:zlib - Enables HTTP inspection of compressed web traffic. Requires dynamicplugin be enabled.
net-analyzer/symon:perl - Enables a generic perl symux client
net-analyzer/symon:symon - Enables the system monitor. Offers no functionality but monitoring and forwarding of measured data
net-analyzer/symon:symux - Enables the multiplexer which stores incoming symon streams on disk in RRD (net-analyzer/rrdtool) files
net-analyzer/tcpdump:chroot - Enable chrooting when dropping privileges
net-analyzer/tcpdump:smi - Build with net-libs/libsmi to load MIBs on the fly to decode SNMP packets
net-analyzer/tcpreplay:pcapnav - Enable if you want the jump to byte offset feature via net-libs/libpcapnav
net-analyzer/tcpreplay:tcpdump - Use net-analyzer/tcpdump for packet decoding feature
net-analyzer/wireshark:ares - Use GNU net-dns/c-ares library to resolve DNS names
net-analyzer/wireshark:doc-pdf - Build documentation in pdf format (US and a4 paper sizes)
net-analyzer/wireshark:gcrypt - Use GNU crypto library (dev-libs/libgcrypt) to decrypt ipsec traffic
net-analyzer/wireshark:pcap - Use net-libs/libpcap for network packet capturing (build dumpcap, rawshark)
net-analyzer/wireshark:smi - Use net-libs/libsmi to resolve numeric OIDs into human readable format
net-dialup/freeradius:udpfromto - Compile in UDPFROMTO support (enables freeradius to specify source address correctly in multi-homed setups)
net-dialup/freeradius-client:scp - Add service type hints derived from username prefix
net-dialup/freeradius-client:shadow - Enable shadow password support
net-dialup/mgetty:fax - Enables 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 active filter support
net-dialup/ppp:atm - Enables ATM (Asynchronous Transfer Mode) protocol support
net-dialup/ppp:dhcp - Installs PPP DHCP client plugin for IP address allocation by a DHCP server (see http://www.netservers.co.uk/gpl/)
net-dialup/ppp:eap-tls - Enables support for Extensible Authentication Protocol and Transport Level Security (see http://www.nikhef.nl/~janjust/ppp/index.html)
net-dialup/ppp:gtk - Installs GTK+ password prompting program that can be used by passprompt.so PPP plugin for reading the password from a X11 input terminal
net-dialup/ppp:ipv6 - Enables support for IP version 6
net-dialup/ppp:mppe-mppc - Enables support for MPPC (Microsoft Point-to-Point Compression) - NEEDS A PATCHED KERNEL <=2.6.14 (see http://mppe-mppc.alphacron.de)
net-dialup/ppp:pam - Enables PAM (Pluggable Authentication Modules) support
net-dialup/ppp:radius - Enables RADIUS support
net-dialup/pptpd:gre-extreme-debug - Log all GRE accepted packages when in debug mode (required if you want upstream support)
net-dialup/xl2tpd:dnsretry - Patch for host lookup retries, activated by redial feature
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:gtk3 - Build the avahi-ui-gtk3 library, and use gtk3 for the avahi utilities under USE=utils
net-dns/avahi:howl-compat - Enable compat libraries for howl
net-dns/avahi:introspection - Use dev-libs/gobject-introspection for introspection
net-dns/avahi:mdnsresponder-compat - Enable compat libraries for mDNSResponder
net-dns/avahi:utils - Install the avahi gtk+ utils avahi-discover, bssh, and bvnc
net-dns/bind:dlz - Enables dynamic loaded zones, 3rd party extension
net-dns/maradns:authonly - Allows one to build only authoritative DNS server
net-dns/mydns:alias - Enable David Phillips aliasing
net-dns/mydns:status - Enable the STATUS opcode to check server status
net-dns/opendnssec:auditor - Enables auditing capabilities for OpenDNSSEC
net-dns/opendnssec:eppclient - Enables support for automatic submission of DNSSEC keys to an upstream epp server
net-dns/opendnssec:external-hsm - Enables support for storing DNSSEC keys through an arbitrary non-portage PKCS#11 interface, specified through an environment variable
net-dns/opendnssec:opensc - Enables support for storing DNSSEC keys through a dev-libs/opensc PKCS#11 interface
net-dns/opendnssec:signer - Enables signing capabilities for OpenDNSSEC
net-dns/opendnssec:softhsm - Enables support for storing DNSSEC keys in a dev-libs/softhsm PKCS#11 object
net-dns/pdns:opendbx - Enable the OpenDBX backend
net-dns/pdnsd:isdn - Linux-only: check status of ippp interfaces with ISDN-specific system calls.
net-dns/pdnsd:urandom - Linux-only: use /dev/urandom (pseudo-random number generation) instead of the default use of random() PRNG.
net-dns/resolvconf-symlink:symlink - Actually replace /etc/resolv.conf with a symlink. Without this flag, the ebuild is a no-op.
net-fs/autofs:sasl - Enable SASL support in the LDAP module
net-fs/cifs-utils:ads - Enable Active Directory support
net-fs/cifs-utils:caps - libcap support
net-fs/cifs-utils:caps-ng - libcap-ng support
net-fs/cifs-utils:creds - cifs credentials support
net-fs/cifs-utils:upcall - Create cifs.idmap binary; idmap support
net-fs/netatalk:appletalk - Build support for Apple's AppleTalk (DDP) protocol and its utilities (atalkd, timelord, papd).
net-fs/netatalk:cups - Add support for net-print/cups printers in papd. This flag is only considered if appletalk USE flag is enabled, and is otherwise ignored.
net-fs/netatalk:quota - Add support for user quota on various filesystems.
net-fs/netatalk:ssl - Use dev-libs/openssl to provide DHX User Access Modules. These are not used with most recent versions of OS X and can be kept disabled without risks.
net-fs/netatalk:xfs - Enable support for XFS Quota
net-im/ejabberd:captcha - Support for CAPTCHA Forms (XEP-158)
net-im/ejabberd:mod_irc - Build irc gateway
net-im/ejabberd:mod_muc - Build Multi User Chat module
net-im/ejabberd:mod_proxy65 - Support for SOCKS5 Bytestreams (XEP-0065)
net-im/ejabberd:mod_pubsub - Build Pubsub module
net-im/ejabberd:mod_statsdx - Measures several statistics, and provides a new section in ejabberd Web Admin to view them.
net-im/ejabberd:web - Enable web admin interface
net-im/ekg2:gadu - Enable Gadu-Gadu protocol support (requires net-libs/libgadu).
net-im/ekg2:gif - GIF token support for Gadu-Gadu protocol.
net-im/ekg2:gnutls - Enable SSL/TLS support through GnuTLS for the plugins supporting it. If 'ssl' is enabled too, GnuTLS will be preferred where possible (and OpenSSL will be used elsewhere).
net-im/ekg2:gpg - Enable jabber message encryption through app-crypt/gpgme.
net-im/ekg2:inotify - Enable inotify-based filesystem moniotoring support for xmsg&mail plugins.
net-im/ekg2:jpeg - JPEG token support for Gadu-Gadu protocol.
net-im/ekg2:oracle - Support logging messages into Oracle database.
net-im/ekg2:sqlite - Support logging messages into SQLite2 database. If 'sqlite3' is set too, it will be used instead.
net-im/ekg2:sqlite3 - Support logging messages into SQLite3 database. If 'sqlite' is set too, SQLite3 will be used.
net-im/ekg2:ssl - Enable the complete SSL/TLS support through OpenSSL. This also enables the 'sim' plugin which relies on OpenSSL.
net-im/empathy:call - Enable Call channel support using net-libs/telepathy-farstream for audio/video calls
net-irc/kvirc:dcc_video - Support video connections over DCC protocol
net-irc/kvirc:dcc_voice - Support voice connections over DCC protocol
net-irc/kvirc:ipc - Support inter-process communication between KVIrc processes
net-irc/kvirc:phonon - Support Phonon for audio output
net-irc/kvirc:qt-dbus - Support Qt-DBus
net-irc/kvirc:transparency - Support pseudo-transparency
net-irc/ngircd:ident - Enables support for net-libs/libident
net-irc/psybnc:multinetwork - Adds support for multiple networks
net-irc/psybnc:oidentd - Adds support for oidentd
net-irc/psybnc:scripting - Adds scripting support
net-irc/quassel:X - Build the Qt 4 GUI client for quassel. If this USE flag is disabled, the GUI is not built, and cannot be used. You might want to disable this on the server, but you need it enabled on the client.
net-irc/quassel:crypt - Support core->network per-channel and per-query blowfish encryption via app-crypt/qca:2.
net-irc/quassel:monolithic - Build Standalone client with integrated core, no external quasselcore needed. Only useful if you don't want to use quassels client/server model. The server and X flags are not needed in this case but it is possible to enable them too.
net-irc/quassel:phonon - Build client with phonon backend support. This enables sound playback in client.
net-irc/quassel:server - Build the server binary. If this USE flag is disabled, the 'core' server binary for quassel is not built, and cannot be used. You need this enabled on the server, but you might want to disable it on the client.
net-irc/quassel:webkit - Use qt-webkit rendering engine for showing URL thumbnails and for other things that need web browser integration.
net-irc/rbot:aspell - Use aspell instead of ispell in the "spell" plugin for rbot. The vanilla plugin uses ispell, but enabling this flag makes it use the ispell interface from aspell instead.
net-irc/rbot:cal - Add dependency over a package providing the /usr/bin/cal command, which is needed to enable the "cal" plugin for rbot. If the USE flag is disabled the plugin is also disabled by default.
net-irc/rbot:dict - Add dependency over dev-ruby/ruby-dict, which is needed to enable the "dict" plugin for rbot. If the USE flag is disabled the plugin is also disabled by default.
net-irc/rbot:figlet - Add dependency over app-misc/figlet, which is used by the "figlet" plugin for rbot. If the USE flag is disabled the plugin will be unable to use figlet; if toilet is also disabled, the plugin will be disabled.
net-irc/rbot:fortune - Add dependency over games-misc/fortune-mod, which is needed to enable the "fortune" plugin for rbot. If the USE flag is disabled the plugin is also disabled by default.
net-irc/rbot:host - Add dependency over net-dns/bind-tools (providing /usr/bin/host), which is needed to enable the "host" plugin for rbot. If the USE flag is disabled the plugin is also disabled by default.
net-irc/rbot:hunspell - Use hunspell instead of ispell in the "spell" plugin for rbot. The vanilla plugin uses ispell, but enabling this flag makes it use the ispell interface from hunspell instead. It's overridden by the aspell USE flag. For native hunspell support check the rbot-hunspell plugin.
net-irc/rbot:nls - Build and install translation for the messages coming from the bot and its plugins (through dev-ruby/ruby-gettext).
net-irc/rbot:shorturl - Add dependency over dev-ruby/shorturl, which is needed to enable the "shortenurl" plugin for rbot. If the USE flag is disabled the plugin is also disabled by default.
net-irc/rbot:timezone - Add dependency over dev-ruby/tzinfo to enable the "time" plugin for rbot. If the USE flag is disabled the plugin is also disabled by default.
net-irc/rbot:toilet - Add dependency over app-misc/toilet, which is used by the "figlet" plugin for rbot. If the USE flag is disabled the plugin will be unable to use toilet; if figlet is also disabled, the plugin will be disabled.
net-irc/rbot:translator - Add dependency over dev-ruby/mechanize, which is needed to enable the "translator" plugin for rbot. If the USE flag is disabled the plugin is also disabled by default.
net-irc/srvx:bahamut - Choose bahamut protocol over p10 protocol
net-irc/supybot:twisted - Allows supybot to use dev-python/twisted as driver
net-irc/unrealircd:extban-stacking - Enable extended channel bans (such as +b ~c: and +b ~n:) to contain other extended bans instead of just hostmasks.
net-libs/daq:afpacket - Build the AFPacket data acquisition module. Functions similar to the PCAP module but with better performance. Snort can run unprivileged when using this module. AFpacket supports both inline and passive modes.
net-libs/daq:dump - Build the Dump data acquisition module. The dump DAQ allows you to test the various inline mode features available in 2.9 Snort like injection and normalization.
net-libs/daq:ipq - Build the IPQ data acquisition module. IPQ is the old way to process iptables packets for inline deployments. Snort can not run unprivileged when using this module.
net-libs/daq:nfq - Build the NFQ data acquisition module. NFQ is the new way to process iptables packets for inline deployments. Snort can not run unprivileged when using this module.
net-libs/daq:pcap - Build the PCAP data acquisition module.
net-libs/libeXosip:srv - enable support for SRV records DNS queries
net-libs/libesmtp:ssl - Enable support for advanced SMTP authentication methods, like NTML and STARTTLS. Also use OpenSSL's MD5 implementation over internal version.
net-libs/libetpan:liblockfile - Enable support for liblockfile library
net-libs/libgsasl:gcrypt - Use dev-libs/libgcrypt for low-level crypto
net-libs/libinfinity:server - Build and install the server binary including init.d/conf.d-scripts. Needed if you want to host an infinote server for gobby.
net-libs/libnids:glib - Use dev-libs/glib for multiprocessing support
net-libs/libnids:libnet - Include code requiring net-libs/libnet
net-libs/liboauth:bindist - Alias for the nss USE flag, since there are license compliancy trouble when using OpenSSL.
net-libs/liboauth:curl - If enabled, net-misc/curl is used thorugh the libcurl library; if it's not, the curl command is used instead. Some features are only available when using the library, but using it as library requires matching SSL implementations.
net-libs/liboauth:nss - Use Mozilla NSS (dev-libs/nss) as hash library; if this is disabled, dev-libs/openssl is used instead.
net-misc/aria2:nettle - Use dev-libs/nettle and dev-libs/gmp for bittorrent/metalink crypto instead of dev-libs/libgcrypt when using net-libs/gnutls for SSL or without SSL support at all.
net-misc/curl:ssh - Enabled SSH urls in curl using libssh2
net-misc/curl:ssl - Enable crypto engine support (via openssl if USE='-gnutls -nss')
net-misc/dahdi:flash - Support (short) flash on FXS
net-misc/dahdi-tools:ppp - Enables PPP/DAHDIRAS support
net-misc/dhcp:client - Install the dhclient program
net-misc/dhcp:server - Install the dhcpd and dhcrelay programs
net-misc/directvnc:mouse - Adds mouse support
net-misc/dnetstats:gnome - Use gksu to gain root access
net-misc/dnetstats:kde - Use kdesu to gain root access
net-misc/dropbear:bsdpty - Add support for legacy BSD pty's rather than dynamic UNIX pty's -- do not use this flag unless you are absolutely sure you actually want it
net-misc/dropbear:multicall - Build all the programs as one little binary (to save space)
net-misc/mediatomb:inotify - Enable inotify filesystem monitoring support
net-misc/mediatomb:lastfm - Enable last.fm support
net-misc/mediatomb:libextractor - Use libextractor to gather files' metadata.
net-misc/mediatomb:mysql - Use dev-db/mysql as backend rather than SQLite3. If this USE flag is disabled, dev-db/sqlite is used instead.
net-misc/mediatomb:taglib - Use media-libs/taglib for reading files' metadata rather than id3lib. If this USE flag is disabled media-libs/id3lib is used instead.
net-misc/mediatomb:thumbnail - Enables video thumbnails generation through media-video/ffmpegthumbnailer
net-misc/memcached:slabs-reassign - Allow manual reassignment of memory slabs at the cost of slab optimizations.
net-misc/mico:findbug - Adds patch to help finding bug#343827
net-misc/networkmanager:wext - Enable support for the deprecated Wext (Wireless Extensions) API; needed for some older drivers (e.g. ipw2200, ndiswrapper)
net-misc/pavuk:hammer - Turn on chunky/hammer mode (DoS) in pavuk: when specified, pavuk will include features to stress test web sites using an ultrahigh performancereplay mechanism
net-misc/ps3mediaserver:transcode - Install optional dependencies for transcoding support via media-video/mplayer
net-misc/ps3mediaserver:tsmuxer - Install optional dependencies for transcoding support via media-video/tsmuxer
net-misc/quagga:bgpclassless - Apply unofficial patch to enable classless prefixes for BGP. Patch and information to be found at http://hasso.linux.ee/doku.php/english:network:quagga
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:pam - Add support for PAM (via sys-libs/pam) to the Quagga Virtual Terminal Interface Shell (vtysh); if the readline USE flag is disabled, this flag is ignored.
net-misc/quagga:readline - Enable support for sys-libs/readline to provide the Quagga Virtual Terminal Interface Shell (vtysh).
net-misc/quagga:tcp-zebra - Enable TCP zserv interface on port 2600 for Zebra/protocol-daemon communication. Unix domain sockets are chosen otherwise.
net-misc/rdesktop:pcsc-lite - Enable smartcard support with sys-apps/pcsc-lite driver
net-misc/scponly:subversion - Enables Subversion compatibility with potential security risks
net-misc/scponly:unison - Enables Unison compatibility with potential security risks
net-misc/scponly:wildcards - Enables wildcard processing with potential security risks
net-misc/scponly:winscp - Enables WinSCP 2.0 compatibility with potential security risks
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 preferred.
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/strongswan:cisco - Enable support for the Cisco VPN client.
net-misc/strongswan:dhcp - Enable server support for querying virtual IP addresses for clients from a DHCP server. (IKEv2 only)
net-misc/strongswan:eap - Enable support for the different EAP modules that is supported.
net-misc/strongswan:farp - Enable faking of ARP responses for virtual IP addresses assigned to clients. (IKEv2 only)
net-misc/strongswan:gcrypt - Enable dev-libs/libgcrypt plugin which provides 3DES, AES, Blowfish, Camellia, CAST, DES, Serpent and Twofish ciphers along with MD4, MD5 and SHA1/2 hash algorithms, RSA and DH groups 1,2,5,14-18 and 22-24(4.4+). Also includes a software random number generator.
net-misc/strongswan:nat-transport - Enable potentially insecure NAT traversal for transport mode in IKEv1. Only enable if you really need this.
net-misc/strongswan:non-root - Force IKEv1/IKEv2 daemons to normal user privileges. This might impose some restrictions mainly to the IKEv1 daemon. Disable only if you really require superuser privileges.
net-misc/strongswan:openssl - Enable dev-libs/openssl plugin which is required for Elliptic Curve Cryptography (DH groups 19-21,25,26) and ECDSA. Also provides 3DES, AES, Blowfish, Camellia, CAST, DES, IDEA and RC5 ciphers along with MD2, MD4, MD5 and SHA1/2 hash algorithms, RSA and DH groups 1,2,5,14-18 and 22-24(4.4+) dev-libs/openssl has to be compiled with USE="-bindist".
net-misc/stunnel:listen-queue - Enable Listen Queue support for Stunnel
net-misc/stunnel:xforward - Enable X-Forwarded-For support for Stunnel
net-misc/termpkg:uucp - Adds support for uucp style device locking
net-misc/tigervnc:server - Build TigerVNC server
net-misc/tigervnc:xorgmodule - Build the Xorg module
net-misc/tightvnc:server - Build vncserver. Allows us to only build server on one machine if set, build only viewer otherwise.
net-misc/wicd:pm-utils - Installs the pm-utils hooks for suspend/resume and requires sys-power/pm-utils
net-misc/x2goserver:fuse - Use sys-fs/sshfs-fuse to allow shared folders
net-misc/yaydl:soundextract - Extract the soundtracks of the downloaded videos
net-nds/389-ds-base:auto-dn-suffix - Enable auto bind with auto dn suffix over unix domain socket (LDAPI) support
net-nds/389-ds-base:autobind - Enable auto bind over unix domain socket (LDAPI) support
net-nds/389-ds-base:bitwise - Enable bitwise plugin - supported data in raw/bitwise format
net-nds/389-ds-base:dna - Enable dna (distributed numeric assignment ) plugin - to automatically assign unique uid numbers to new user entries as they are created.
net-nds/389-ds-base:ldapi - Enable LDAP over unix domain socket (LDAPI) support
net-nds/389-ds-base:pam-passthru - Enable pam-passthru plugin - for simple and fast system services used in ldap
net-print/hplip:minimal - Only build internal hpijs/hpcups driver (not recommended at all, make sure you know what you are doing)
net-print/hplip:parport - Enable parallel port for devices which require it
net-print/hplip:qt4 - Enable graphical interface using Qt 4
net-print/hplip:scanner - Enable scanner on multifunction devices which support it
net-print/hplip:snmp - Add support for net-analyzer/net-snmp which enables this driver to work over networks (both for server and client)
net-print/hplip:static-ppds - Use statically-generated PPDs instead of Dynamic PPDs. Although this is deprecated some printers may still need it to work properly. Use this flag if hp-setup fails to find/create a valid PPD file
net-print/magicfilter:lprng-failsafe - Refuse options for compability with certain LPRng versions.
net-proxy/dansguardian:kaspersky - Adds support for Kaspersky AntiVirus software
net-proxy/dansguardian:ntlm - Enable support for the NTLM auth plugin
net-proxy/tinyproxy:xtinyproxy-header - Include the X-Tinyproxy header
net-proxy/tsocks:tordns - Apply tordns patch which allows transparent TORification of the DNS queries
net-proxy/ufdbguard:doc - Download and install the ufdbguard reference manual in PDF.
net-proxy/ufdbguard:httpd - Build, install and start the provided mini-http daemon with the redirect CGI integrated. Since there is no way to tell ufdbguard to not start it, this is a build-time option.
net-voip/ekiga:gconf - Enable GConf support
net-voip/ekiga:h323 - Enable H.323 protocol
net-voip/ekiga:shm - Enable the Shared Memory Extension from libXext
net-voip/ekiga:static - Statically link to opal and ptlib
net-voip/ekiga:xcap - Enable XML Configuration Access Protocal
net-voip/linphone:video - Enable video support (display/capture)
net-voip/sflphone:doxygen - Support for building documentation with doxygen
net-voip/sflphone:iax - Support for IAX (Inter Asterisk eXchange)
net-voip/yate:h323 - Build H.323 Channel plugin
net-voip/yate:ilbc - Build ILBC codec plugin
net-voip/yate:sctp - Support for Stream Control Transmission Protocol
net-voip/yate:spandsp - Enable support for the spandsp codec
net-wireless/bluez:consolekit - Use sys-auth/pambase[consolekit] to determine access to bluetooth devices based on whether a user is logged in locally or remotely
net-wireless/bluez:test-programs - Install tools for testing of various Bluetooth functions
net-wireless/gnome-bluetooth:introspection - Use dev-libs/gobject-introspection for introspection
net-wireless/gnome-bluetooth:nautilus - Build the gnome-extra/nautilus-sendto plugin
net-wireless/gnome-bluetooth:sendto - Build the gnome-extra/nautilus-sendto plugin
net-wireless/kismet:suid - Install a setuid root helper binary with limited functionality; this allows running kismet as a normal user, significantly reducing security risks
net-wireless/madwifi-ng:injection - Adds support for net-wireless/aircrack-ng aireplay-ng packet injection
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/exonerate:utils - Install all utilities
sci-biology/fasta:icc - Use intel compiler instead of gcc
sci-biology/gmap:goby - Enable support for goby
sci-biology/gmap:samtools - Enable support for samtools
sci-biology/goby:cpp - Compile C/C++ API
sci-biology/hmmer:pvm - Add support for parallel virtual machine (sys-cluster/pvm)
sci-biology/mcl:blast - add support for NCBI BLAST data
sci-biology/plink:R - add support R language
sci-biology/plink:webcheck - add support for online update checking every time the program starts
sci-biology/raxml:sse3 - Enable optimization for SSE3 capable chips
sci-biology/tophat:bam - Compile support for the BAM format
sci-biology/ucsc-genome-browser:server - Install genome browser Web application. If this flag is off, only libraries and utilities from the suite are installed.
sci-biology/yass:dmalloc - Enable debugging with the dmalloc library
sci-biology/yass:lowmem - Build for environments with low amounts of memory
sci-chemistry/PyMca:matplotlib - Support for plotting through matplotlib
sci-chemistry/apbs:arpack - Include support for arpack libs
sci-chemistry/apbs:fetk - Include support for FeTK
sci-chemistry/apbs:tools - Install optional tools
sci-chemistry/avogadro:glsl - Enable glsl features via GLEW.
sci-geosciences/gmt:gmtfull - Full resolution bathymetry database
sci-geosciences/gmt:gmthigh - Add high resolution bathymetry database
sci-geosciences/gmt:gmttria - Non GNU triangulation method, more efficient
sci-geosciences/gmt:metric - Use SI (cm) units instead of US (inches) ones
sci-geosciences/gmt:mex - Enable compilation of mex supplement which requires Octave/Matlab
sci-geosciences/gmt:octave - Enable octave support
sci-geosciences/googleearth:mdns-bundled - Use bundled nss-mdns library instead of depending on sys-auth/nss-mdns. Enable this if you want to avoid the deptree.
sci-geosciences/googleearth:qt-bundled - Use bundled Qt4 libraries instead of system ones. Recommended only for troubleshooting.
sci-geosciences/gpsd:dbus - export gpsd data over dbus connections
sci-geosciences/gpsd:ntp - Enable net-misc/ntp shared memory interface and PPS kernel support for GPS time
sci-geosciences/gpsd:shm - export gpsd over shared memory
sci-geosciences/gpsd:sockets - export gpsd over unix sockets
sci-geosciences/grass:gmath - Enable gmath wrapper for BLAS/Lapack (virtual/blas, virtual/lapack)
sci-mathematics/isabelle:CTT - CTT (Constructive Type Theory) is an extensional version of Martin-Löf's Type Theory.
sci-mathematics/isabelle:Cube - Cube (The Lambda Cube)
sci-mathematics/isabelle:FOL - FOL (Many-sorted First-Order Logic) provides basic classical and intuitionistic first-order logic. It is polymorphic.
sci-mathematics/isabelle:FOLP - FOLP (FOL with Proof Terms)
sci-mathematics/isabelle:HOL - (Higher-Order Logic) is a version of classical higher-order logic resembling that of the HOL System.
sci-mathematics/isabelle:LCF - LCF (Logic of Computable Functions)
sci-mathematics/isabelle:Pure - Pure is the basis for all object-logics.
sci-mathematics/isabelle:Sequents - Sequents (first-order, modal and linear logics)
sci-mathematics/isabelle:ZF - ZF (Set Theory) offers a formulation of Zermelo-Fraenkel set theory on top of FOL.
sci-mathematics/isabelle:graphbrowsing - Generate theory browsing information, including HTML documents that show a theory's definition, the theorems proved in its ML file and the relationship with its ancestors and descendants.
sci-mathematics/unuran:prng - Use sci-mathematics/prng library
sci-mathematics/unuran:rngstreams - Use sci-mathematics/rngstreams library
sci-mathematics/yacas:server - Build the network server version
sci-misc/boinc:cuda - Use nvidia cuda toolkit for speeding up computations. NOTE: works only for subset of nvidia graphic cards so make sure your card is supported before opening bug about it.
sci-misc/h5utils:hdf - Build hdf to hdf5 (and vice-versa) converter
sys-apps/pacman:gpg - Support verifying packages signed with GPG using app-crypt/gpgme
sys-apps/paludis:pbins - Enable binary package support. Adds dependency upon app-arch/libarchive
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:prebuilt-documentation - Use pre-built documentation
sys-apps/paludis:python-bindings - Enable Python bindings. Requires a lot of RAM to build (~700Mbytes per job) and adds a dependency upon dev-libs/boost
sys-apps/pcmciautils:staticsocket - Add support for static sockets
sys-apps/pcsc-lite:libusb - Use dev-libs/libusb detection to hotplug new smartcard readers. This flag should only be enabled if you're running a non-Linux kernel or you don't want to use sys-fs/udev.
sys-apps/pcsc-lite:udev - Use sys-fs/udev rules to handle devices' permissions and hotplug support. Unless you know what you're doing do not disable this flag on Linux kernels. This is provided as an option for completeness.
sys-apps/pcsc-lite:usb - Use dev-libs/libusb detection to hotplug new smartcard readers. This flag only makes sense on non-Linux systems, as on Linux, sys-fs/udev is used instead.
sys-apps/pcsc-tools:network-cron - Monthly cronjob the update-smartcard_list script
sys-apps/tcp-wrappers:netgroups - Support matching NIS (host) netgroup names via the @netgroup syntax (if you don't know what this means, you most likely need want it)
sys-auth/pam_mktemp:prevent-removal - If supported, set EXT2_APPEND_FL on /tmp/.private to prevent temporary directories from being removed
sys-auth/pam_mysql:openssl - Use OpenSSL for md5 and sha1 support
sys-auth/pam_pkcs11:nss - Use Mozilla NSS (dev-libs/nss) as provider for PKCS#11 access, rather than using OpenSSL with a custom implementation of the PKC#11 protocol.
sys-auth/pam_pkcs11:pcsc-lite - Build the card_eventmanager binary used to detect card removal and lock the sessions. This needs sys-apps/pcsc-lite.
sys-auth/pambase:consolekit - Enable pam_ck_connector module on local system logins. This allows for console logins to make use of ConsoleKit authorization.
sys-auth/pambase:cracklib - Enable pam_cracklib module on system authentication stack. This produces warnings when changing password to something easily crackable. It requires the same USE flag to be enabled on sys-libs/pam or system login might be impossible.
sys-auth/pambase:debug - Enable debug information logging on syslog(3) for all the modules supporting this in the system authentication and system login stacks.
sys-auth/pambase:gnome-keyring - Enable pam_gnome_keyring module on system login stack. This enables proper Gnome Keyring access to logins, whether they are done with the login shell, a Desktop Manager or a remote login systems such as SSH.
sys-auth/pambase:minimal - Disables the standard PAM modules that provide extra information to users on login; this includes pam_tally (and pam_tally2 for Linux PAM 1.1 and later), pam_lastlog, pam_motd and other similar modules. This might not be a good idea on a multi-user system but could reduce slightly the overhead on single-user non-networked systems.
sys-auth/pambase:mktemp - Enable pam_mktemp module on system auth stack for session handling. This module creates a private temporary directory for the user, and sets TMP and TMPDIR accordingly.
sys-auth/pambase:pam_krb5 - Enable pam_krb5 module on system auth stack, as an alternative to pam_unix. If Kerberos authentication succeed, only pam_unix will be ignore, and all the other modules will proceed as usual, including Gnome Keyring and other session modules. It requires sys-libs/pam as PAM implementation.
sys-auth/pambase:pam_ssh - Enable pam_ssh module on system auth stack for authentication and session handling. This module will accept as password the passphrase of a private SSH key (one of ~/.ssh/id_rsa, ~/.ssh/id_dsa or ~/.ssh/identity), and will spawn an ssh-agent instance to cache the open key.
sys-auth/pambase:passwdqc - Enable pam_passwdqc module on system auth stack for password quality validation. This is an alternative to pam_cracklib producing warnings, rejecting or providing example passwords when changing your system password. It is used by default by OpenWall GNU/*/Linux and by FreeBSD.
sys-auth/pambase:sha512 - Switch Linux-PAM's pam_unix module to use sha512 for passwords hashes rather than MD5. This option requires >=sys-libs/pam-1.0.1 built against >=sys-libs/glibc-2.7, if it's built against an earlier version, it will silently be ignored, and MD5 hashes will be used. All the passwords changed after this USE flag is enabled will be saved to the shadow file hashed using SHA512 function. The password previously saved will be left untouched. Please note that while SHA512-hashed passwords will still be recognised if the USE flag is removed, the shadow file will not be compatible with systems using an earlier glibc version.
sys-block/gparted:btrfs - Include Btrfs support (sys-fs/btrfs-progs)
sys-block/gparted:dmraid - Support for dmraid devices, also known as ATA-RAID, or Fake RAID.
sys-block/gparted:fat - Include FAT16/FAT32 support (sys-fs/dosfstools)
sys-block/gparted:gtk - Enable .desktop support for gtk+ based desktops.
sys-block/gparted:hfs - Include HFS support (sys-fs/hfsutils)
sys-block/gparted:jfs - Include JFS support (sys-fs/jfsutils)
sys-block/gparted:mdadm - Support for Linux software RAID.
sys-block/gparted:ntfs - Include NTFS support (sys-fs/ntfsprogs)
sys-block/gparted:reiser4 - Include ReiserFS4 support (sys-fs/reiser4progs)
sys-block/gparted:reiserfs - Include ReiserFS support (sys-fs/reiserfsprogs)
sys-block/gparted:xfs - Include XFS support (sys-fs/xfsprogs, sys-fs/xfsdump)
sys-block/open-iscsi:modules - Build the open-iscsi kernel modules
sys-block/open-iscsi:utils - Build the open-iscsi utilities
sys-block/parted:debug - Enable debugging as encouraged by upstream: [The default configuration] includes --enable-debug (by default), which contains many assertions. Obviously, these "waste" space, but in the past, they have caught potentially dangerous bugs before they would have done damage, so we think it's worth it. Also, it means we get more bug reports ;)
sys-block/parted:device-mapper - Enable sys-fs/device-mapper support in parted
sys-block/partimage:nologin - Do not include login support when connecting partimaged
sys-block/tgt:fcoe - Add support for FCoE protocol
sys-block/tgt:fcp - Add support for new FC protocol
sys-block/tgt:ibmvio - Add support for IBM Virtual I/O
sys-boot/grub:device-mapper - Enable support for sys-fs/device-mapper
sys-boot/grub:efiemu - Build and install the efiemu runtimes
sys-cluster/torque:server - Enable compilation of pbs_server and pbs_sched
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/binutils-apple:lto - Add support for Link-Time Optimization with LLVM
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/clang:multitarget - Build all host targets (default: host only)
sys-devel/clang:static-analyzer - Install the Clang static analyzer
sys-devel/clang:system-cxx-headers - By default, clang++ searchs for C++ headers in a series of hardcoded paths. Enabling this flag will force it to use the active gcc profile ones
sys-devel/distcc:crossdev - Enable support for sys-devel/crossdev
sys-devel/distcc:gssapi - Enable support for net-libs/libgssglue
sys-devel/gcc:d - Enable support for the D programming language
sys-devel/gcc:fixed-point - Enable fixed-point arithmetic support for MIPS targets in gcc (Warning: significantly increases compile time!)
sys-devel/gcc:go - Build the GCC Go language frontend.
sys-devel/gcc:graphite - Add support for the framework for loop optimizations based on a polyhedral intermediate representation
sys-devel/gcc:gtk - Useful only when building GCJ, this enables Abstract Window Toolkit (AWT) peer support on top of GTK+
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:libssp - Build SSP support into a dedicated library rather than use the code in the C library (DO NOT ENABLE THIS IF YOU DON'T KNOW WHAT IT DOES)
sys-devel/gcc:lto - Add support for link-time optimizations (unsupported, use at your own risk).
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-apple:multislot - Allow for SLOTs to include minor version (3.3.4 instead of just 3.3)
sys-devel/gcc-apple:objc - Build support for the Objective C code language
sys-devel/gcc-apple:objc++ - Build support for the Objective C++ language
sys-devel/gettext:cvs - When running `autopoint`, use cvs to store the internal development files; this requires cvs at runtime, but will be faster/smaller than raw archives
sys-devel/gettext:git - When running `autopoint`, use git to store the internal development files; this requires git at runtime, but will be faster/smaller than raw archives
sys-devel/kgcc64:multislot - Allow for SLOTs to include minor version (eg. 3.3.4 instead of just 3.3)
sys-devel/libperl:ithreads - Enable Perl threads, has some compatibility problems
sys-devel/llvm:gold - Build the gold linker plugin
sys-devel/llvm:llvm-gcc - Build LLVM with sys-devel/llvm-gcc
sys-devel/llvm:multitarget - Build all host targets (default: host only)
sys-devel/llvm:udis86 - Enable support for dev-libs/udis86 disassembler library
sys-devel/sparse:gtk - Build the test-inspect utility (requires x11-libs/gtk+ version 2)
sys-devel/sparse:xml - Build the c2xml utility (requires dev-libs/libxml2).
sys-freebsd/freebsd-sbin:ipfilter - Build tools to administer the ipfilter firewall.
sys-freebsd/freebsd-sbin:netware - Build libraries and tools to work with NetWare protocols (IPX and NCP).
sys-freebsd/freebsd-sbin:pf - Build tools to administer the PF firewall.
sys-freebsd/freebsd-share:isdn - Enable ISDN support
sys-freebsd/freebsd-ubin:ar - Build FreeBSD's ar and ranlib replacements based on libarchive. The toolchain will still use binutils' version but you can play with it. They have been renamed to freebsd-ar and freebsd-ranlib not to collide with binutils.
sys-fs/lessfs:filelog - Enable the ability to log to a file instead of syslog
sys-fs/lessfs:memtrace - Enable leefs to create a report regarding the memory allocation. This feature should be used for debugging purposes to avoid performance degradation
sys-fs/loop-aes:aes-ni - Enable support for Intel's AES instruction set
sys-fs/loop-aes:extra-ciphers - Enable extra ciphers
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:lvm1 - Allow users to build lvm2 with lvm1 support
sys-fs/lvm2:nolvmstatic - Allow users to build lvm2 dynamically
sys-kernel/openvz-sources:deblob - Remove binary blobs from kernel sources to provide libre license compliance.
sys-kernel/pf-sources:deblob - Remove binary blobs from kernel sources to provide libre license compliance.
sys-kernel/pf-sources:experimental - Apply patches that are considered experimental. For more information, check out the ChangeLog or the ebuild that interests you.
sys-kernel/rt-sources:deblob - Remove binary blobs from kernel sources to provide libre license compliance.
sys-kernel/vanilla-sources:deblob - Remove binary blobs from kernel sources to provide libre license compliance.
sys-kernel/vserver-sources:deblob - Remove binary blobs from kernel sources to provide libre license compliance.
sys-kernel/zen-sources:minimal - Clone git tree with --depth 1 to reduce amount of data to download. Use with caution
sys-libs/gdbm:berkdb - enable compatibility layer for UNIX-like dbm and ndbm interfaces
sys-libs/gdbm:exporter - enable gdbmexport binary for exporting data from gdbm-1.8 databases into gdbm-1.9
sys-libs/ncurses:ada - Add bindings for the ADA programming language
sys-libs/ncurses:trace - Enable test trace() support in ncurses calls
sys-libs/pam:audit - Enable support for sys-process/audit
sys-libs/pam:berkdb - Build the pam_userdb module, that allows to authenticate users against a Berkeley DB file. Please note that enabling this USE flag will create a PAM module that links to the Berkeley DB (as provided by sys-libs/db) installed in /usr/lib and will thus not work for boot-critical services authentication.
sys-libs/pam:cracklib - Build the pam_cracklib module, that allows to verify the chosen passwords' strength through the use of sys-libs/cracklib. Please note that simply enabling the USE flag on this package will not make use of pam_cracklib by default, you should also enable it in sys-auth/pambase as well as update your configuration files.
sys-libs/talloc:compat - Enable extra compatibility stuff
sys-libs/talloc:swig - Install interface definitions for dev-lang/swig
sys-process/fcron:debug - Enable debug code and output. Since version 3.0.5 this will no longer force foreground execution, and fcron will be able to run as a service properly.
sys-process/fcron:pam - Enable PAM support for fcron. This means that fcron will pass through the "fcron" stack before executing the jobs, and fcrontab will use the "fcrontab" stack to authenticate the user before editing its crontab file.
sys-process/htop:openvz - Enable openvz support
sys-process/htop:vserver - Enable vserver support
sys-process/lsof:rpc - support looking up RPC service info
www-apache/mod_security:curl - Build the ModSecurity Audit Log Collector (mlogc) that depends on net-misc/curl.
www-apache/mod_security:geoip - Configure ModSecurity to query the GeoIP database from MaxMind, provided by dev-libs/geoip. This flag only controls the default configuration, as the GeoIP query code is part of ModSecurity's source code.
www-apache/mod_security:jit - Add support for the PCRE Just-in-Time optimisation, as enabled by dev-libs/libpcre with jit USE flag enabled. Might not be available on hardened systems.
www-client/seamonkey:ipc - Use inter-process communication between tabs and plugins. Allows for greater stability in case of plugin crashes
www-client/seamonkey:mailclient - Build Mozilla's Mail client (default on)
www-client/seamonkey:methodjit - Enable JIT for JavaScript using MethodJIT for faster JS performance. Hardened users can disable this USE-flag to use MPROTECT on grsecurity kernels.
www-client/seamonkey:roaming - Build roaming extension support (default on)
www-client/seamonkey:system-sqlite - Use the system-wide dev-db/sqlite installation with secure-delete enabled
www-client/seamonkey:webm - Use system media-libs/libvpx for HTML5 WebM video support.
www-client/torbrowser:torprofile - Install pre-configured profile folder by upstream into "/usr/share/torbrowser/profile" (you still have to copy it in place)
www-plugins/adobe-flash:kde - Enables a KCM plugin for configuring flash player preferences
www-plugins/adobe-flash:sse2check - This flag, enabled by default, will check for sse2 support on your cpu and die if not found. If you are remote-building this package, you can disable this flag but you have been warned
www-servers/uwsgi:carbon - Enable support for sending statistics to a carbon server (see http://projects.unbit.it/uwsgi/wiki/Carbon).
www-servers/uwsgi:erlang - Let the uWSGI server as as an Erlang C-Node and exchange messages and rpc with Erlang nodes. Together with the USE=python this enables erlang support in python (see the mappings table in http://projects.unbit.it/uwsgi/wiki/ErlangIntegration).
www-servers/uwsgi:zeromq - Enable logging and deployment via ZeroMQ. Together with json-support this turns uwsgi into a Mongrel2 handler (see http://projects.unbit.it/uwsgi/wiki/Mongrel2).
x11-libs/cairo:cleartype - Add ClearType-style behavior for sub-pixel hinting. Patch taken from Arch Linux
x11-libs/cairo:drm - Use Linux DRM for backend acceleration
x11-libs/cairo:gallium - Use Mesa's Gallium backend for acceleration
x11-libs/cairo:glib - Compile with GLib Object System support
x11-libs/cairo:lcdfilter - Add FreeType LCD filtering, ClearType-style behavior for sub-pixel-hinting. Overrides cleartype USE flag. Patch taken from Ubuntu
x11-libs/cairo:opengl - Use Mesa backend for acceleration
x11-libs/cairo:openvg - Use OpenVG for backend acceleration
x11-libs/qt-assistant:compat - Build the extra compatibility layer required by a few packages, see http://labs.qt.nokia.com/2010/06/22/qt-assistant-compat-version-available-as-extra-source-package/
x11-libs/qt-gui:raster - Use the alternative 'raster' graphicssystem as default rendering engine
x11-libs/qt-gui:trace - Build the 'trace' graphicssystem engine which allows to record all drawing operations into a trace buffer. Later it can be replayed with the qttracereplay utility
x11-plugins/bfm:gkrellm - Enable building of app-admin/gkrellm module
x11-plugins/compiz-plugins-extra:gconf - Install GConf schemas for the plugins, needed when using the GConf-based configuration backend in x11-wm/compiz.
x11-plugins/compiz-plugins-main:gconf - Install GConf schemas for the plugins, needed when using the GConf-based configuration backend in x11-wm/compiz.
x11-plugins/pidgin-mbpurple:twitgin - Enable graphical plugin for Gtk+ interface of Pidgin.
x11-terms/rxvt-unicode:buffer-on-clear - Store visible output to history buffer when clearing the screen with ctrl-l. Read https://bbs.archlinux.org/viewtopic.php?id=129302
x11-terms/rxvt-unicode:secondary-wheel - Support for wheel scrolling on secondary screens (like mutt). Read http://lists.schmorp.de/pipermail/rxvt-unicode/2011q4/001491.html
x11-wm/compiz:fuse - Enables support for the filesystem in userspace plugin through sys-fs/fuse.
x11-wm/compiz:gconf - Enable the GConf-based configuration backend; it is not required to work with GNOME, and might actually be faster if it's not used.
x11-wm/compiz-fusion:emerald - Install the x11-wm/emerald package.
x11-wm/compiz-fusion:unsupported - Install the x11-plugins/compiz-fusion-plugins-unsupported package.
x11-wm/echinus:xrandr - Enable support for multihead configuration
x11-wm/enlightenment:pango - Enable pango font rendering
x11-wm/enlightenment:xrandr - Enable support for the X xrandr extension
x11-wm/fluxbox:bidi - Enable bidirectional language support with dev-libs/fribidi
x11-wm/fluxbox:newmousefocus - Patches the focus model to the upcoming 1.1.2 model, which adds a new 'StrictMouseFocus' mode
x11-wm/fluxbox:slit - Enables the fluxbox slit (or dock)
x11-wm/fluxbox:toolbar - Enables the fluxbox toolbar
x11-wm/fvwm:gtk2-perl - Enable GTK2 Perl bindings
x11-wm/fvwm:lock - Enable screen locking
x11-wm/fvwm:netpbm - Enable NetPBM support (used by FvwmScript-ScreenDump)
x11-wm/fvwm:rplay - Enable rplay support
x11-wm/fvwm:stroke - Mouse Gesture support
x11-wm/matchbox-common:pda - Support for pda folders
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.