Cocos simplifies game creation and distribution with Cocos Creator
Voxel game-creation platform with easy modding and game creation
Multi Theft Auto is a game engine
A multi core friendly rigid body physics and collision detection lib
Solar2D Game Engine main repository (ex Corona SDK)
Multi-platform 2D and 3D game engine
3D Game engine with editor
Magic Another Game Engine
The Tiny JavaScript Game Engine That Can!
Open game and rendering engine packed into a JavaScript framework
The game engine for everyone
fheroes2 is a recreation of Heroes of Might and Magic II game engine
Flax Engine, multi-platform 3D game engine
Powerful, mature open-source cross-platform game engine for Python
Cross-Platform C++ 2D/3D game engine
Voxel game engine in C++ with OpenGL
Open-source engine for Heroes of Might and Magic III
dhewm 3 main repository
Free, cross-platform 2D game engine powered by Haxe and OpenFL
Cross-platform 2D and 3D game engine with modular architecture
The flexible game engine
The ioquake3 community effort to continue supporting/developing id's
RPG Maker 2000/2003 and EasyRPG games interpreter
Multi-platform Engine for Desktop, XBOX (UWP) and Mobile games
Recreation of the classic Grand Theft Auto III game executable