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
A retro game engine for Python
Multi Theft Auto is a game engine
fheroes2 is a recreation of Heroes of Might and Magic II game engine
Solar2D Game Engine main repository (ex Corona SDK)
The ioquake3 community effort to continue supporting/developing id's
A game engine powered by python and panda3d
Voxel game-creation platform with easy modding and game creation
Open game and rendering engine packed into a JavaScript framework
The game engine for everyone
LayaAir is an open-source 2D/3D engine
Real Time Strategy game engine supporting early Westwood classics
Fast and lightweight JavaScript game engine built on WebGL and glTF
Free game engine for development of desktop, mobile, and web games
Open source voxel game engine with support for survival and crafting
Multi-platform 2D and 3D game engine
Magic Another Game Engine
A complete 3-D game development suite written in Java
Stride (formerly Xenko), a free and open-source cross-platform C# game
Xash3D FWGS engine
A quick and easy to use drag and drop retro game creator
The flexible game engine
The Tiny JavaScript Game Engine That Can!