LABjs
Loading And Blocking JavaScript: On-demand parallel loader for JavaScript with execution order dependencies
Kefir
A Reactive Programming library for JavaScript
RequireJS
A file and module loader for JavaScript
Hermes.js
Message and Error logger implementation
Fishbone.js
A super lightweight (½kb) JavaScript library with automatic method chaining, automatic context binding, event support and simple inheritance. c-{{{-<
Simplate
A simple, but powerful, templating engine for JavaScript.
When
A solid, fast Promises/A+ and when() implementation, plus other async goodies.
Fast.js
Faster user-land reimplementations for several common builtin native JavaScript functions.
Do T
The fastest + concise javascript template engine for nodejs and browsers. Partials, custom delimiters and more.
Script.js
Asyncronous JavaScript loader and dependency manager
Mjml
MJML: the only framework that makes responsive-email easy
Google Closure Library
git-svn mirror of Google's Closure Library.
Twitterlib
Twitter JavaScript API library
Path.js
Simple, lightweight routing for web browsers
JsRender
A light-weight but powerful templating engine, highly extensible, without DOM or jQuery dependency.
101
A modern JS utility library
Lodash
An alternative to Underscore.js, delivering consistency, customization, performance, and extra features.