Godot is a powerful cross-platform game engine
Xash3D FWGS engine
Injectable LUA scripting system, SDK generator, live property editor
Multi Theft Auto is a game engine
Open source voxel game engine with support for survival and crafting
Real Time Strategy game engine supporting early Westwood classics
The game engine for everyone
The Ren'Py Visual Novel Engine
Open-source engine for Heroes of Might and Magic III
The ioquake3 community effort to continue supporting/developing id's
Voxel game-creation platform with easy modding and game creation
Solar2D Game Engine main repository (ex Corona SDK)
A complete 3-D game development suite written in Java
A game engine powered by python and panda3d
dhewm 3 main repository
Fast and lightweight JavaScript game engine built on WebGL and glTF
Free game engine for development of desktop, mobile, and web games
A modular Common Lisp game engine
fheroes2 is a recreation of Heroes of Might and Magic II game engine
A 2D rigid body physics engine for the web
A game framework written with osu! in mind.
An easy to use 2D HTML5 game engine written in TypeScript
A retro game engine for Python
Cross-Platform C++ 2D/3D game engine
A refreshingly simple data-driven game engine built in Rust