phina.js is game library
JSIso - An HTML5 Canvas Tile Engine
Blend4Web is a tool for interactive 3D visualization on the Internet
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.
Framework for HTML5 Canvas oriented 2D video games
Frozen is an open-source HTML5 game engine delivering ease-of-use, rapid development through tooling and modularity.
A Joyful 2D HTML5 Game Engine.
html5 game engine optimized for rapid development