Melon JS
a fresh & lightweight javascript game engine
Nipplejs
A virtual joystick for touch capable interfaces.
Turbulenz Engine
Turbulenz is a modular 3D and 2D game framework for making HTML5 powered games for browsers and mobile devices.
Rot.js
ROguelike Toolkit
Chem
html5 game engine optimized for rapid development
Blend4 Web
Blend4Web is a tool for interactive 3D visualization on the Internet
Crafty
Crafty is a JavaScript game library that can help you create games in a structured way.
Easystar.js
An asynchronous A* pathfinding API written in Javascript.
Joy.js
A Joyful 2D HTML5 Game Engine.
Phina.js
phina.js is game library
Flash JS
JavaScript graphics and games engine with API familiar to Flash one. Just look to examples sources.
Superpowers Core
:octopus: Superpowers — Extensible HTML5 app for real-time collaborative projects
Cutjs
Lightweight, fast, interactable 2D HTML5 rendering engine for cross-platform game development.
Gamejs
GameJs is a thin library on top of the HTML canvas element. In addition to the drawing functions it has a set of generally helpful modules for game development.
Canvas Engine
Framework for HTML5 Canvas oriented 2D video games
Lychee JS
Environment-Independent JavaScript engine (HTML5 Canvas, V8GL, WebGL, native OpenGL, NodeJS)
Limejs
HTML5 game framework for web and iOS