Wordcount.js
Calculate file newlines, word, and byte counts on client side using HTML5 File API. (Emulates Linux's wc command)
Contra
Asynchronous flow control with a functional taste to it
Csso
CSS-optimizer
Csscomb.js
CSS coding style formatter
Bem Core
BEM Core Library
jQuery Evergreen
Small & fast DOM and event library for modern browsers.
Clndr
a jQuery calendar plugin that uses HTML templates
Klass
a utility for creating expressive classes in JavaScript
Underscore.db
Pure JavaScript database based on Underscore for Node, node-webkit and the browser
JS Xlsx
Javascript XLSX / XLSM / XLSB (Excel 2007+) parser and (one day) writer
Tangle
a JavaScript library for reactive documents
Jade
Jade - robust, elegant, feature rich template engine for nodejs
Serenade.js
Client side MVC framework
Underscore String
String manipulation extensions for Underscore.js javascript library.
Switchery
iOS 7 style switches for your checkboxes