Open 3D Engine (O3DE) is an Apache 2.0-licensed multi-platform 3D
Godot is a powerful cross-platform game engine
The Ren'Py Visual Novel Engine
Multi Theft Auto is a game engine
Xash3D FWGS engine
Open source voxel game engine with support for survival and crafting
The game engine for everyone
A complete 3-D game development suite written in Java
Real Time Strategy game engine supporting early Westwood classics
Open-source engine for Heroes of Might and Magic III
A game engine powered by python and panda3d
Solar2D Game Engine main repository (ex Corona SDK)
Cocos simplifies game creation and distribution with Cocos Creator
Descent 3 by Outrage Entertainment
Multi-platform 2D and 3D game engine
Fast and lightweight JavaScript game engine built on WebGL and glTF
fheroes2 is a recreation of Heroes of Might and Magic II game engine
A multi core friendly rigid body physics and collision detection lib
Powerful, mature open-source cross-platform game engine for Python
The ioquake3 community effort to continue supporting/developing id's
A 2D rigid body physics engine for the web
Voxel game-creation platform with easy modding and game creation
dhewm 3 main repository
The flexible game engine
A retro game engine for Python