ActiveJS : ActiveJS is a JavaScript application framework that provides local and REST based data modeling and pure DOM view construction with back button and hi...
The HTML5 Shiv : The HTML5 Shiv enables use of HTML5 sectioning elements in legacy Internet Explorer and provides basic HTML5 styling for Internet Explorer 6-9, Safari...
SPF : A lightweight JS framework for fast navigation and page updates from YouTube
Ember.js : A JavaScript framework for creating ambitious web applications
Styletron : Styletron is a universal CSS-in-JS engine built from the ground up for high-performance.
Rainbow is a code syntax highlighting library written in Javascript.
It was designed to be lightweight (1.4kb), easy to use, and extendable.
It is completely themable via CSS.