Pixi.js
Super fast HTML 5 2D rendering engine that uses webGL with canvas fallback
Babylon.js
Babylon.js: a complete JavaScript framework for building 3D games with HTML 5 and WebGL
Phaser
Phaser is a light-weight 2D game framework for making HTML5 games for desktop and mobile browsers
Matter JS
a 2D rigid body physics engine for the web
Melon JS
a fresh & lightweight javascript game engine
Egret Core
Egret is a brand new open mobile game and application engine which allows you to quickly build mobile games and apps on Android,iOS and Windows.
Turbulenz Engine
Turbulenz is a modular 3D and 2D game framework for making HTML5 powered games for browsers and mobile devices.
Crafty
Crafty is a JavaScript game library that can help you create games in a structured way.
Rot.js
ROguelike Toolkit
Nipplejs
A virtual joystick for touch capable interfaces.
PhysicsJS
A modular, extendable, and easy-to-use physics engine for javascript
Cutjs
Lightweight, fast, interactable 2D HTML5 rendering engine for cross-platform game development.
Verlet JS
A simple Verlet physics engine written in javascript
Enchant.js
A simple JavaScript framework for creating games and apps
Superpowers Core
:octopus: Superpowers — Extensible HTML5 app for real-time collaborative projects
Easystar.js
An asynchronous A* pathfinding API written in Javascript.
Limejs
HTML5 game framework for web and iOS