Free, open source game engine online
Parse and serialize minecraft packets, plus authentication
A high-performance, industry-standard 2D physics engine built on Box2D
A 2D rigid body physics engine for the web
Ct.js is a desktop game engine that makes learning programming fun
Bitburner Game
Quiz communiste et anarchiste du Front étudiant uni (Québec)
Main repository with actual Space Station 13 sources
Massively multiplayer online game server and client framework
Deck of cards (old version)
Simple data driven web based gamebook engine using javascript.
An extensible development framework for roleplay games.