RPG Maker 2000/2003 and EasyRPG games interpreter
Voxel game-creation platform with easy modding and game creation
The Ren'Py Visual Novel Engine
Multi Theft Auto is a game engine
Magic Another Game Engine
Game engine supporting many 3D/2D formats and graphic effects
Full featured MUD server with all the trimmings.
A conservative source port of Hexen that is identical to DOS
Spring is a free RTS engine developed for Windows, Linux and Mac OS X.
An online multiplayer turn based strategy game and board game engine.
Built to be ease of use, with no programming knowledge, Multi-platform
C++ Text Adventure Engine
Point-and-click 2D game engine
OSGET is the first open source mobile game engine template.
Free MMORPG Engine. Develop and host graphical browser-based games.