Godot is a powerful cross-platform game engine
Multi Theft Auto is a game engine
Xash3D FWGS engine
The Ren'Py Visual Novel Engine
Voxel game-creation platform with easy modding and game creation
The game engine for everyone
The flexible game engine
Open source voxel game engine with support for survival and crafting
A game engine powered by python and panda3d
Real Time Strategy game engine supporting early Westwood classics
dhewm 3 main repository
The HTML5 Creation Engine
A complete 3-D game development suite written in Java
fheroes2 is a recreation of Heroes of Might and Magic II game engine
Solar2D Game Engine main repository (ex Corona SDK)
Fast and lightweight JavaScript game engine built on WebGL and glTF
Cocos simplifies game creation and distribution with Cocos Creator
The ioquake3 community effort to continue supporting/developing id's
Powerful, mature open-source cross-platform game engine for Python
A refreshingly simple data-driven game engine built in Rust
Open-source engine for Heroes of Might and Magic III
Cross-Platform C++ 2D/3D game engine
Voxel game engine in C++ with OpenGL
Recreation of the classic Grand Theft Auto III game executable
Free game engine for development of desktop, mobile, and web games