Snabbt.js
Fast animations with javascript and CSS transforms
Turn.js
The page flip effect for HTML5
Gif.js
JavaScript GIF encoding library
Rot.js
ROguelike Toolkit
Alertify.js
JavaScript Alert/Notification System
Rivets
Declarative data binding facility
Mavo
Create web applications entirely by writing HTML and CSS!
Swig
Take a swig of the best template engine for JavaScript.
jScrollPane
Pretty, customisable, cross browser replacement scrollbars
Alloy Ui
Alloy is a UI metaframework that provides a consistent and simple API for building web applications across allthree levels of the browser: structure, style and behavior.
Spectrum
The No Hassle JavaScript Colorpicker
Vorlonjs
A new, open source, extensible, platform-agnostic tool for remotely debugging and testing your JavaScript. Powered by node.js and socket.io
Bootstrap Wysiwyg
Tiny bootstrap-compatible WISWYG rich text editor
jQuery.maskedinput
jQuery Masked Input Plugin
Layzr.js
A small, fast, modern, and dependency-free library for lazy loading.
Es6 Shim
ECMAScript 6 (Harmony) compatibility shims for legacy JavaScript engines
Stacktrace.js
Framework-agnostic, micro-library for getting stack traces in all web browsers