Svgeezy
Allows for automatic Image fallbacks for browsers that can't handle SVGs
Stapes
a (really) tiny Javascript MVC microframework
Objgrep
Find strings inside complicated javascript objects
Minified.js
Replace jQuery or MooTools with a <4kB Library
Limejs
HTML5 game framework for web and iOS
Image Picker
Image Picker is a simple jQuery plugin that transforms a select element into a more user friendly graphical interface.
Augment.js
Modern JavaScript in your IE
Apitizer
API mocking for client JavaScript applications
Mask Js
Zen Coding | Markup | Template | HMVC
jCanvas
A jQuery plugin that makes the HTML5 canvas easy to work with.
Tagmanager
A jQuery plugin (working nicely with twitter bootstrap)
Lity
Lightweight responsive lightbox.
Gremlins.js
Monkey testing library for web apps and Node.js
Color
JavaScript color conversion and manipulation library
Functional Js
A functional js library that facilitates currying and point-free / tacit programming
Flickity
:leaves: Touch, responsive, flickable carousels
Zoomooz
An easy-to-use jQuery plugin for making zooming web pages.