Mahasona engine is an open source game engine.
Cross platform 2D/3D game engine written in C++11 & OpenGL ES 2/3
Cross platform Game Creation Software
Gives agents personality, moods, emotions and emotional attachments.
Educational framework for OpenGLES, OpenCL and OpenAL
A generic 2D engine for any kind of game
a game library to develop audio games
C++ Framework for slot machine games
Kinect based controller.
C library for manipulating Minecraft world data
Scriptable frontend for media applications.
A graphics engine + toolkit.
A tool for editing OHRRPGCE RPG files
Little game background framework in java.
Cross-platform reimplementation of AMOS BASIC (runtime)
Java game engine for shoot 'em ups, using Java2D.
A cross-platform OpenGL based lightweight scenegraph library
Cross-platform 2D game engine
A cross platform 3d c++ game engine
also download updates from files section
Zap Engine