Intern : Intern is a complete test system for JavaScript designed to help you write and run consistent, high-quality test cases for your JavaScript libraries a...
css3-mediaqueries-js : make CSS3 Media Queries work in all browsers (JavaScript library)
Mousetrap : A simple library for handling keyboard shortcuts in Javascript.
Leaflet : A Modern, Lightweight Open-Source JavaScript Library for Interactive Maps
Crafty : JavaScript Game Engine, HTML5 Game Engine
Add Clippy or his friends to any website for instant nostalgia.