Desktop/Android/HTML5/iOS Java game development framework
UCI chess engine
Cocos simplifies game creation and distribution with Cocos Creator
Solar2D Game Engine main repository (ex Corona SDK)
Open-source OpenGL/SDL2 reimplementation of Sid Meier's Alpha Centauri
Multi-platform 2D and 3D game engine
scene-oriented, flexible 3D engine (C++, Python, C#, Java)
3D modeler, 3D game maker, 3D demo maker
A promising chess program
Orx: Data-Driven Game Engine
0 A.D. is a free, open-source, cross-platform real-time strategy game.
Urho3D Game engine
MAME Android Emulator.
A 2D game engine and level editor
A cross-platform 2D game engine
Easy fine console input/output for java
Karel - 3D language interpreter
C/C++ , PHP, PYTHON, 3D ENGINES, CHROME NATIVE CLIENT
Classic pac-man on Qt with pure C++.
Realtime 3D engine for game development
The Atomic Game Engine is a multi-platform 2D and 3D engine
Open-source, cross-platform, C++ game engine for creating 2D/3D games
Android, DOS, FirefoxOS, Linux, MacOS and Windows all in one..
Open Game Bootstrap