Cross-platform 2D and 3D game engine with modular architecture
The ioquake3 community effort to continue supporting/developing id's
Multi-platform Engine for Desktop, XBOX (UWP) and Mobile games
Magic Another Game Engine
Voxel game engine in C++ with OpenGL
Free game engine for development of desktop, mobile, and web games
3D and 2D game engine written in Rust
An easy to use 2D HTML5 game engine written in TypeScript
Stride (formerly Xenko), a free and open-source cross-platform C# game
dhewm 3 main repository
JavaScript-based game engine designed to empower developers
scene-oriented, flexible 3D engine (C++, Python, C#, Java)
The Tiny JavaScript Game Engine That Can!
Ct.js is a desktop game engine that makes learning programming fun
A 2D rigid body physics engine for the web
Zig game engine & graphics toolkit
Open source library for creative expression on the web, desktop, etc.
A tool to easily transform Unreal Engine games into VR experiences
Full featured MUD server with all the trimmings.
GemRB is a portable open-source implementation of the Infinity Engine
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
The multiplayer game engine
A completely free, open-source, 2D game engine