Civ II Evolution Project

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

The Genius

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

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/

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/

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 Basic, Phy
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/

Kabal Invasion

A game module for Nova Gaming System, an open source web based game with servers worldwide.
http://sourceforge.net/projects/kabalinvasion

Open Game Source

A web magazine devoted to open source game development.
http://www.identicalsoftware.com/ogs/

SecurePlay Open Source Development SDKs

Build games on Secureplay sourcecode libraries in Flash/Java C++. Create secure game transactions for multiplayer games (player management, state/event control, random events, secret events) Platform independent Encrypted pluggable communications.
http://www.secureplay.com/products/products.htm

UFO Alien Invasion

UFO:AI is a 3d turn based strategy game inspired by the X-Com series by Microprose.
http://ufo.myexp.de

PlanetPenguin Racer

An OpenGL racing game featuring Tux, the Linux mascot. The goal of the game is to slide down a snow- and ice-covered mountain as quickly as possible.(C++,TCL) [Linux,MacOS X]
http://racer.planetpenguin.de

CompWebChess.com

This open source application allows users to run a free email/live online chess chess web site.
http://www.compwebchess.com

Enigma

A puzzle game based on oxyd. Runs on Windows, OS X, and most open source operating systems. (C++) [GPL]
http://www.nongnu.org/enigma/

PlanetPhillip

Commentary, analysis and research of sci-fi single player first person shooters.
http://www.planetphillip.com/

Csharks

Csharks is a game developing firm in India which creates games in multiple platforms (DirectX,Flash,J2ME,Director,OpenGL) at tight deadlines, at International quality levels.
http://www.Csharks.com

Small Apps and Games

Small apps and games developments.
http://www.freewebs.com/elfofthefire/index.htm

Hot Potato Online

This game is a fast paced arena sport where players try to explode the opposition using a short-fused potato bomb.
http://www.hotpotatoonline.com

Merchant Empires: Profit&Prey

A multiplayer, web-based game of space exploration and economic competition. It is a game of strategy, role-playing, combat, and diplomacy.
http://www.merchantempires.com/

BNW - Brave New World - The Official Site of The OpenSource Game

Official Site of The Brave New World game an OpenSource Game Project. The game is real time strategy. (Delphi)
http://bnw.sourceforge.net/

Spice Trade

Colonize Europe in this Java based, open source game. Live an adventure in the 12th century world.
http://www.spicetrade.org/

Cows and Bulls game

Free games, open source and tutorials for various programming languages.
http://www.examsguide.com/opensource/games.html

Eclipse-game

Eclipse is a driving and FPS style shooting game with comprehensive campaign. Story takes place on surface of Moon. OpenGL graphics and original soundtrack. Single-player game only.
http://www.drzizka.adslink.cz/Eclipse.html

SpyWar

SpyWar is an online startegic game in development phase.
http://spywar.sourceforge.net/

Daimonin

Free isometric real-time MMORPG. 2d/3d graphics, 3d sound effects, digital ambient music.
http://www.daimonin.net

Open Source Gaming

A portal about Open Source Gaming. Newsfeed, articles, downloads, forum, links.
http://osgaming.net/