Nipplejs
A virtual joystick for touch capable interfaces.
Matter JS
a 2D rigid body physics engine for the web
Turbulenz Engine
Turbulenz is a modular 3D and 2D game framework for making HTML5 powered games for browsers and mobile devices.
Superpowers Core
:octopus: Superpowers — Extensible HTML5 app for real-time collaborative projects
Chem
html5 game engine optimized for rapid development
Rot.js
ROguelike Toolkit
Coquette
A micro framework for JavaScript games
Cutjs
Lightweight, fast, interactable 2D HTML5 rendering engine for cross-platform game development.
Phina.js
phina.js is game library
Tmlib.js
JavaScript をより使いやすく, より便利に, そしてより豊かに.
Joy.js
A Joyful 2D HTML5 Game Engine.
Crafty
Crafty is a JavaScript game library that can help you create games in a structured way.
Kiwi.js
Kiwi.js is a blazingly fast mobile & desktop browser based HTML5 game framework. It uses CocoonJS for publishing to the AppStore.
Lychee JS
Environment-Independent JavaScript engine (HTML5 Canvas, V8GL, WebGL, native OpenGL, NodeJS)
Panda.js
Panda.js HTML5 game engine
Isometric
JSIso - An HTML5 Canvas Tile Engine
Flash JS
JavaScript graphics and games engine with API familiar to Flash one. Just look to examples sources.