Free game engine for development of desktop, mobile, and web games
The game engine for everyone
Voxel game engine in C++ with OpenGL
Fast and lightweight JavaScript game engine built on WebGL and glTF
Multi-platform Engine for Desktop, XBOX (UWP) and Mobile games
The ioquake3 community effort to continue supporting/developing id's
A modular Common Lisp game engine
Cross-platform 2D and 3D game engine with modular architecture
The Tiny JavaScript Game Engine That Can!
A Flutter based game engine
Ct.js is a desktop game engine that makes learning programming fun
2D JavaScript Physics Engine
Open source library for creative expression on the web, desktop, etc.
Stride (formerly Xenko), a free and open-source cross-platform C# game
scene-oriented, flexible 3D engine (C++, Python, C#, Java)
A high-performance, industry-standard 2D physics engine built on Box2D
3D and 2D game engine written in Rust
A completely free, open-source, 2D game engine
Full featured MUD server with all the trimmings.
GemRB is a portable open-source implementation of the Infinity Engine
A 2D rigid body physics engine for the web
PyCAPGE - Python Classic Adventure Point and Click Game Engine
Game engine supporting many 3D/2D formats and graphic effects
A cell-based puzzle game featuring classic and completely new puzzles
JavaScript-based game engine designed to empower developers