Multi Theft Auto is a game engine
The game engine for everyone
C++ lightweight cross-platform game engine
Orx: Data-Driven Game Engine
Mini game engine for games104
scriptable game engine with built-in support for 2D graphics and sound
TurboSphere is an easy to learn and powerful JS based game engine.
A 3D, fully concurrent game engine
3D game engine for C and C++
Zen3D is a 3D engine and editor for creating games