1. Enquire.js : Handle CSS Media Queries With JS
3. OriDOmi : Fold Up HTML Elements Like Paper
4. Gauge.js : Animated Gauges with HTML5 Canvas
5. Big Screen
6. Underscore.String : Useful String Manipulation Extension
Underscore.string provides you several useful functions: capitalize, clean, includes, count, escapeHTML, unescapeHTML, insert, splice, startsWith, endsWith, titleize, trim, truncate and so on. It is released under MIT License.
Resumable.js allows uploads to automatically resume uploading after a network connection is lost either locally or to the server. Additionally, it allows for users to pause and resume uploads without losing state. Currently, it is limited to Firefox 4+ and Chrome 11+.
8. Tangle : Create Reactive Documents
TangleKit is an optional collection of UI components that let your readers adjust values and visualize the results. You can grab whichever components you want, use them, extend them, modify them, or just learn from them and make your own. TangleKit also includes (and depends on) a few helpful libraries, such as MooTools, sprintf, and BVTouchable.