0 A.D. is a free, open-source, cross-platform real-time strategy game.
Molecular viewer and prototyping framework
XML-based framework for developing games
2D Game Engine
ZED OS the clone of Windows XP
The imaginary eight-bit machine
Javascript Canvas Framework
3D urban environment renderer : browser-app ; as well as a GTA clone
TurboSphere is an easy to learn and powerful JS based game engine.
SuperWikia: The Runtime/Realtime Environment for Codesmiths
Javascript adventure game engine
An extensible development framework for roleplay games.
Horror Game Project
Space + Planet Simulation in a voxel-like world
Free MMORPG Engine. Develop and host graphical browser-based games.