meSpeak.js : meSpeak.js (modulary enhanced speak.js) is a 100% client-side JavaScript text-to-speech library
TraceKit : Not all browsers support stack traces on error objects, but TraceKit squeezes out as much useful information as possible and normalizes it.
Ember.js : A JavaScript framework for creating ambitious web applications
Crafty : JavaScript Game Engine, HTML5 Game Engine
cssQuery() : cssQuery() is a powerful cross-browser JavaScript function that enables querying of a DOM document using CSS selectors. All CSS1 and CSS2 selectors ar...
JavaScript Libraries for adding offline support to web apps.