You can make it - Open Source MMORPG Platform
Arianne is an engine to develop multiplayer online games like Stendhal
Game engine supporting many 3D/2D formats and graphic effects
A free 3D game engine to create games and realtimes scenes for Windows
Spring is a free RTS engine developed for Windows, Linux and Mac OS X.
A Project which shall result in a Remake of the classic game
Example code for creating a 2D platform game in Java.
A graphic adventure game
Simple data driven web based gamebook engine using javascript.
Single-/multi-player card game Mau Mau (similar to UNO®)
Built to be ease of use, with no programming knowledge, Multi-platform
Toolkit for the easy prototyping of hybrid games for Tabletop Devices
Cross platform Game Creation Software
Gives agents personality, moods, emotions and emotional attachments.
2D top down arcade shooter
Text-based adventure game creator and player. Comes with demo games.
This game is a 2d arcade game. You can move, jump, kill monster.
Read and write PGN format and test moves for legality.