Solar2D Game Engine main repository (ex Corona SDK)
Cocos simplifies game creation and distribution with Cocos Creator
Multi-platform Engine for Desktop, XBOX (UWP) and Mobile games
Multi-platform 2D and 3D game engine
Flax Engine, multi-platform 3D game engine
Cross-platform 2D and 3D game engine with modular architecture
Cross-Platform C++ 2D/3D game engine
A game engine with an emphasis on real-time cutting-edge solutions
Voxel game-creation platform with easy modding and game creation
The game engine for everyone
GemRB is a portable open-source implementation of the Infinity Engine
scene-oriented, flexible 3D engine (C++, Python, C#, Java)
Open-source engine for Heroes of Might and Magic III
Multi Theft Auto is a game engine
Open 3D Engine (O3DE) is an Apache 2.0-licensed multi-platform 3D
N64 Game-Engine and Editor using libdragon & tiny3d
UCI chess engine
Recreation of the classic Grand Theft Auto III game executable
A certain block game
Descent 3 by Outrage Entertainment
Desktop/Android/HTML5/iOS Java game development framework
Powerful, mature open-source cross-platform game engine for Python
fheroes2 is a recreation of Heroes of Might and Magic II game engine
YimMenu, a GTA V menu protecting against a wide ranges
Write your game with TypeScript in UE or Unity