Stars
Select2 is a jQuery based replacement for select boxes. It supports searching, remote data sets, and infinite scrolling of results.
An HTML5 saveAs() FileSaver implementation
typeahead.js is a fast and fully-featured autocomplete library
Knockout makes it easier to create rich, responsive UIs with JavaScript
A lightning fast JavaScript grid/spreadsheet
Compatibility implementation of the ECMAScript Internationalization API (ECMA-402) for JavaScript -- UNMAINTAINED
A validation library for Knockout JS
Compile & Minify Less/Sass/Stylus/Css/JS/CoffeeScript/LiveScript files. Integrates with MVC and ServiceStack
A collection of enhanced binding syntaxes using Knockout 3+
KoLite contains a set of helpers to aid in creating MVVM applications using JavaScript and Knockout.
DurandalJs combined with jQuery Mobile using the default DurandalJs Starterkit Application.