JavaScript framework to build game engines, games, emulators and apps
Open Game Bootstrap
Cross platform 2D/3D game engine written in C++11 & OpenGL ES 2/3
Cross platform Game Creation Software
A generic 2D engine for any kind of game
A very small multi-platform game engine for creating desktop games.
Open Source Virtual World and MMOG Development Platform
Cross-platform reimplementation of AMOS BASIC (runtime)
CM Game Development Kit