Open source library for creative expression on the web, desktop, etc.
ThinkPHP Framework
INSTEAD - Simple Text Adventure Interpreter.
JavaScript framework to build game engines, games, emulators and apps
2D Game Engine
A cross platform Lua based game engine
Multidocument automation by templates - for sphinx, mkdocs, epydoc ...
Asphyre is a cross-platform framework for Delphi and FreePascal.
Event driven concurrent framework for Python
Cross platform 2D/3D game engine written in C++11 & OpenGL ES 2/3
Cross-platform C framework very compact libraries and tools.
Scriptable frontend for media applications.
Hungry Hero is an open source Flash game built on Starling Framework.