Fate  
   A massive multiplayer space trading and combat game for Linux. [GPL]
   http://fate.sourceforge.net/

Hawk Software  
   Developer of the open source HAWK game engine, and the OpenNL portable networking library for Windows.
   http://www.hawksoft.com/

Civ II Evolution Project  
   Developing an Open Source strategy game based on Sid Meier's Civilization II. Public project.
   http://c-evo.org/

Tux Racer  
   An Open Source project in which the user takes the form of Tux (the Linux Mascot) and races downhill through alpine trails.
   http://tuxracer.sourceforge.net

Playing the Open Source Game  
   Shawn Hargreaves has several Open Source projects and interesting articles about the future of Open Source games.
   http://www.talula.demon.co.uk

Linux Game Development Center  
   The LGDC provides concise and accurate articles about Linux gaming news, development tutorials, and reviews of the latest tools and resources.
   http://lgdc.sunsite.dk/index.html

phpRPG  
   phpRPG is a multiplayer fantasy role playing game driven by PHP and MySQL, with aims to develop a web-based game engine which shares common qualities between multiple user dungeons (MUDs), paper & pen RPGs and computer RPGs.
   http://phprpg.org

21st Century Trader  
   This little addictive game contains the same elements used in games like drugwars, except with a space theme.
   http://home.mweb.co.za/iw/iwdymond/thedomain/index.htm?

Adonthell  
   A fantasy RPG game available for Linux, FreeBSD and BeOS. MacOS and Windows support will come soon.
   http://adonthell.linuxgames.com

Merchant Empires  
   Multiplayer web-based game of space exploration and economic competition.
   http://www.advancedpowers.com/

Snip  
   Open-source Tetris implementation.
   http://snip.sourceforge.net

K2W RPG  
   A collection of open source client, server, and editor to build online role playing games.
   http://www.k2wrpg.org/

The Genius  
   Chess engine including artificial intelligence, user interface and several features.
   http://thegenius.sourceforge.net

Quantum Star SE  
   Quantum Star SE is a browser based space strategy game involving Mining, Combat, Exploration, Planets and Clans played in real time. (PHP/SQL)[Platform Independent]
   http://www.quantum-star.com

Blacknova Traders  
   Web-based, multi-player space exploration and strategy game (PHP) [OS Independent].
   http://www.blacknova.net/

FreeDroid  
   Clone of the classic game "Paradroid". (C, Python) [MacOS, Windows 95/98/2000, Linux]
   http://freedroid.sourceforge.net/

Final Frontier Trader  
   2D single player space strategy, combat, and trading game. (C++) [OS Independent]
   http://fftrader.sourceforge.net

Groundfire  
   A 2D real-time multiplayer tank battling game. (C++) [Windows 9X/2000/XP, Linux]
   http://www.groundfire.net/

Danger from the Deep  
   Danger from the deep (aka dangerdeep) is a Free / Open Source World War II german submarine simulation. [Linux / Windows] (C++)
   http://dangerdeep.sourceforge.net

Machinations  
   Developing a Real-Time Strategy
   http://machinations.sourceforge.net/

Sekoya - open source mmorpg  
   Sekoya is a gathering of students trying to develop nice open source games. Our main project is a MMORPG running under Linux and Windows.
   http://sekoya-games.sourceforge.net/

jQuizShow  
   Free quiz game based on the "Who Wants to Be a Millionaire" game show. Add your own questions for classroom use or for fun. [Java, OS Independent, GPL]
   http://quizshow.sourceforge.net

upload - Israeli Developers Stage  
   Provides developers with a place to upload, meet, share, exchange ideas & codes, software & games, build, improve, bug-fix, read, redistribute, and modify the source code of contributions submitted to the site. (C/C++/VC++,Delphi,Pascal,Visual Ba
   http://www.upload.co.il

Right Wing Smackdown Game  
   Right Wing Smackdown Game. The game for the whole violent leftist family. For any unix command line, including OS X.
   http://www.lancemiller.org/rightwing_smackdown/

Flight Gear Flight Simulator  
   The FlightGear flight simulator project is an open-source, multi-platform, cooperative flight simulator development project. Source code for the entire project is available. (OpenGL)[OS Independent]
   http://www.flightgear.org/