Hungry Hero is an open source Flash game built on Starling Framework.
Open Source Virtual World and MMOG Development Platform
cross-platform 2d game engine
Investigo - DX9 Performance and Debugging Toolkit
A cross-platform OpenGL based lightweight scenegraph library
AMOS BASIC reimplementation in Java
Cross-platform 2D game engine
A cross platform 3d c++ game engine
Game framework on top of Python, Panda3D and Twisted
also download updates from files section
Read and write PGN format and test moves for legality.
The Lambda-Engine is a cross platform game engine.
Make games with Lego-like building blocks