Featherlight
Featherlight is a very lightweight jQuery lightbox plugin. It's simple yet flexible and easy to use. Featherlight has minimal css and uses no inline styles, everything is name-spaced, it's completely customizable via config object and offers image, ajax and iframe support out of the box. Featherlights small footprint weights about 4kB – in total.
Baguette Box.js
Simple and easy to use lightbox script written in pure JavaScript
Proton
A particle engine for html5
Typeit
The most versatile JavaScript typewriter effect library on the planet.
Grid
Drag and drop library for two-dimensional, resizable and responsive lists
Smoothie
Smoothie Charts: smooooooth JavaScript charts for realtime streaming data
JS Plumb
jQuery/MooTools/YUI3 Javascript library that lets you connect parts of your UI together.
Remote Storage
Client-side Javascript library to make apps compatible with a remote storage.
Rainbow
Simple syntax highlighting library written in javascript
Shuffle
jQuery Shuffle Plugin
Swipebox
A touchable jQuery lightbox
Twig.js
JS implementation of the Twig Templating Language
Responsive Slides
Simple & lightweight responsive slider plugin (in 1kb)
Keypress
A keyboard input capturing utility in which any key can be a modifier key.
Jquery Tokeninput
Tokeninput is a jQuery plugin which allows your users to select multiple items from a predefined list, using autocompletion as they type to find each item. You may have seen a similar type of text entry when filling in the recipients field sending messages on facebook.
Oimo.js
Lightweight 3d physics engine for javascript