Cocos simplifies game creation and distribution with Cocos Creator
Flax Engine, multi-platform 3D game engine
A game engine with an emphasis on real-time cutting-edge solutions
Multi-platform 2D and 3D game engine
Cross-platform 2D and 3D game engine with modular architecture
Multi-platform Engine for Desktop, XBOX (UWP) and Mobile games
Cross-Platform C++ 2D/3D game engine
Solar2D Game Engine main repository (ex Corona SDK)
Open 3D Engine (O3DE) is an Apache 2.0-licensed multi-platform 3D
Recreation of the classic Grand Theft Auto III game executable
Multi Theft Auto is a game engine
Descent 3 by Outrage Entertainment
Open-source engine for Heroes of Might and Magic III
fheroes2 is a recreation of Heroes of Might and Magic II game engine
Powerful, mature open-source cross-platform game engine for Python
Voxel game-creation platform with easy modding and game creation
scene-oriented, flexible 3D engine (C++, Python, C#, Java)
The game engine for everyone
3D Game engine with editor
Free game engine for development of desktop, mobile, and web games
Open source clone of the Age of Empires II engine
A multi core friendly rigid body physics and collision detection lib
3D Procedural Game Engine Using OpenGL
3D game engine with lua scripting
RTSish Game Engine