Letter: T
- TeXmacs - Structured wysiwyg scientific text editor
- Terminal - X Terminal Emulator
- Thunar - Thunar File Manager
- TurboGears - Back-to-front web development in Python
- t1lib - PostScript Type 1 font rasterizer
- t1utils - Collection of Type 1 and 2 font manipulation utilities
- taarich - Tells the Hebrew date, Torah readings, and generates calendars
- tachyon - Parallel / Multiprocessor Ray Tracing System
- taglib - Audio Meta-Data Library
- tagtool - Ogg Vorbis and MP3 tag manager
- tango-icon-theme - Icons from Tango Project
- tango-icon-theme-extras - Extra Icons from the Tango Project
- taskjuggler - Project management tool
- tasks - Tasks to-do list
- tastymenu - KMenu replacement
- taxipilot - Game where you pilot a taxi in space
- tbcload - Tcl bytecode loader
- tcd-utils - TCD (Tide Constituent Database) Utils
- tcl-thread - Tcl Thread extension
- tclabc - A Tcl interface and a Tk GUI to the ABC notation
- tclchecker - Tcl syntax checker
- tclcompiler - Tcl bytecode compiler
- tcldebugger - Tcl debugging library
- tcldom - TclDOM is a package that provides a DOM binding for the Tcl scripting language
- tclhttpd - Extensible Web+Application server written in Tcl
- tcllib - The standard Tcl library
- tclparser - Tcl syntax parser
- tclpro - Development and debugging tools for Tcl applications
- tclsoap - Tcl commands for SOAP remote procedure calls
- tcltls - OpenSSL extension for Tcl
- tclxml - TclXML is a package that provides XML parsing for the Tcl scripting language
- tcpick - A tcp stream sniffer, tracker and capturer
- tcpreplay - Replay captured network traffic
- tcptraceroute - A traceroute implementation using TCP packets
- tcputils - Utilities for TCP programming in shell-scripts
- tcpxtract - Tool for extracting files from network traffic
- tdom - DOM parser for Tcl
- tecnoballz - A Brick Busting game
- telepathy-butterfly - MSN connection manager for Telepathy
- telepathy-feed - A Galago feed for Telepathy
- telepathy-filesystem - Telepathy filesystem layout
- telepathy-gabble - A Jabber/XMPP connection manager
- telepathy-idle - IRC connection manager for Telepathy
- telepathy-mission-control - Central control for Telepathy connection manager
- telepathy-stream-engine - Telepathy client to handle media streaming
- telescope-server - Opensource Telescope control servers to interface with stellarium
- tellico - A collection manager
- tempest - Tempest OpenGL screensaver
- tenr-de-styles-pkg - A collection of styles for fluxbox
- terminus-font - Clean fixed width font
- testdisk - Tool to check and undelete partition
- tetex-IEEEtran - Official LaTeX class for IEEE transactions journals and conferences
- tetex-bytefield - Create illustrations for network protocol specifications
- tetex-dvipost - LaTeX post filter command to support change bars and overstrike mode
- tetex-elsevier - Elsevier LaTeX style files and documentation
- tetex-eurofont - Provides a command that prints a euro symbol
- tetex-font-cm-lgc - CM-LGC Type1 fonts for LaTeX
- tetex-font-kerkis - Kerkis type 1 fonts for LaTeX
- tetex-fonts-hebrew - Culmus Hebrew fonts support for tetex
- tetex-perltex - Define LaTeX macros in terms of Perl code
- tetex-prosper - LaTeX class for writing transparencies
- tetex-tex4ht - Translates TeX and LaTeX into HTML or XML+MathML
- tetex-unicode - Unicode support for LaTeX
- tetrinetx - The GNU TetriNET server
- texmaker - LaTeX editor
- tgif - 2-D drawing tool
- themes-backgrounds-gnome - Assorted Backgrounds from art.gnome.org
- theora-exp - Experimental theora decoder
- thewidgetfactory - A tool for previewing GTK widgets
- thinkfinger - A driver for the UPEK/SGS Thomson Microelectronics fingerprint reader
- thttpd - Tiny, turbo, throttleable lightweight http server
- thunar-archive-plugin - Archive plugin for the Thunar file manager
- thunar-media-tags-plugin - Media Tags plugin for the Thunar file manager
- thunar-volman - Automatic management of removable drives and media for the Thunar file manager
- tibetan-machine-uni-fonts - Tibetan Machine Uni font for Tibetan, Dzongkha and Ladakhi
- tideEditor - Editor for Tide Constituent Database (TCD) files
- tidy - Utility to clean up and pretty print HTML/XHTML/XML
- tiger - Security auditing on UNIX systems
- tilda - A quake like terminal for GNOME
- tile - Modernized widgets for Tk
- tin - Basic Internet news reader
- tinyca2 - Simple graphical userinterface to manage a small CA
- tinyerp - Open Source ERP Client
- tinyfugue - A MU* client
- tiobench - Threaded I/O benchmark
- tiquit - A PHP5-compatible help desk incident tracking/knowledgebase system
- tkcon - Tcl GUI console
- tkcvs - TkCVS and TkDiff
- tkdnd - Tk extension that adds native drag & drop capabilities
- tklib - Collection of widgets and other packages for Tk
- tktable - Table/matrix widget extension to Tcl/Tk
- tla - GNU arch revision control system
- tmda - Tagged Message Delivery Agent
- tolua++ - A tool to integrate C/C++ code with Lua
- tomoe - Japanese handwritten input system
- tong - A mixture of two classic games
- toped - IC Layout Editor
- tor - Anonymizing overlay network for TCP (The onion router)
- torcs - The Open Racing Car Simulator
- torcs-data - The Open Racing Car Simulator data files
- torque - Tera-scale Open-source Resource and QUEue manager
- torsmo - TyopoytaORvelo System MOnitor
- tpb - ThinkPad button support utility
- trac - Enhanced wiki and issue tracking system
- trac-bazaar-plugin - Bazaar plugin for Trac
- trac-git-plugin - GIT version control plugin for Trac
- trac-mercurial-plugin - Mercurial plugin for Trac
- trac-webadmin - Web interface for administration of Trac
- trackballs - Steer a marble ball through a labyrinth
- trackballs-music - In-game music for Trackballs
- tracker - An object database, tag/metadata database, search tool and indexer
- translate-toolkit - A collection of tools to assist software localization
- transmission - A lightweight GTK+ BitTorrent client
- tre - POSIX compatible regexp library with approximate matching
- treecc - Tree Compiler Compiler
- tremulous - First Person Shooter game based on the Quake 3 engine
- tremulous-data - Data files for tremulous the FPS game
- tripwire - IDS (Intrusion Detection System)
- ttywatch - Log output of arbitrarily many devices
- turba - The Horde contact management application
- tuxpaint - Drawing program designed for young children
- tuxpaint-stamps - Extra stamp files for tuxpaint
- tuxpuck - 3D Shufflepuck Pong Game
- tuxtype2 - Tux Typing, an educational typing tutor for children
- twinkle - A SIP Soft Phone