Gideros Release version
Colonize the New World.
Air traffic control tower and radar simulator (solo + multi-player)
Game engine supporting many 3D/2D formats and graphic effects
LGSL (Live Game for PHP 5.4-8+: online status for various gameservers
A game engine for console based text games
Extensible Line-drawing & Polygon-filling Rasterization Libs for Java
Open source revival of the game Transarctica / Arctic Baron
Spring is a free RTS engine developed for Windows, Linux and Mac OS X.
Fixes for X-Wing game binaries
Software to help people run and organize tournaments.
3D-Accelerated open-source DOOM engine
Creates D&D monsters for use with Pathfinder ruleset
3D .NET engine for Windows, Linux, Mac
Multi-platform game engine similar to old Megaman with a stage editor
Cross platform BrakeOut with level editor
Built to be ease of use, with no programming knowledge, Multi-platform
A QuakeWorld package containing everything needed to play QW right now