Ct.js is a desktop game engine that makes learning programming fun
JavaScript-based game engine designed to empower developers
You can make it - Open Source MMORPG Platform
Contains the code for CM-SS13
An elegant Go board and SGF editor for a more civilized age
Web powered cross-platform 3D, WebXR game engine
Main repository with actual Space Station 13 sources
Massively multiplayer online game server and client framework
Multiplayer online game using Phaser + WebSocket (Socket.IO)
A comprehensive path-finding library for grid based games
Egret is a brand new open mobile game and application engine
An extensible development framework for roleplay games.