Vis
Dynamic, browser-based visualization library
When
A solid, fast Promises/A+ and when() implementation, plus other async goodies.
Angular History
A history service for AngularJS. Undo/redo, that sort of thing. Has nothing to do with the "back" button, unless you want it to.
Speakingurl
Generate of so called "static" or "nice-looking" or "slug" or "SpeakingURL" from a string.
Humane.js
A simple, modern, browser notification system
Visibility.js
Visibility.js allows you to determine whether your web page is visible to a user, is hidden in background tab or is prerendering. It allows you to use the page visibility state in JavaScript logic and improve browser performance by disabling unnecessary timers and AJAX requests, or improve user interface experience (for example, by stopping video playback or slideshow when user switches to another browser tab).
Jsface
Small, fast, elegant, powerful, and cross platform JavaScript OOP library. Support main(), singleton, super call, private, mixins, plugins, AOP and more.
Contra
Asynchronous flow control with a functional taste to it
Meld
AOP for JS with before, around, on, afterReturning, afterThrowing, after advice, and pointcuts
Jquery Timeago
Timeago is a jQuery plugin that makes it easy to support automatically updating fuzzy timestamps (e.g. "4 minutes ago").
Tweet
put twitter on your website with tweet, an unobtrusive javascript plugin for jquery
Bottlejs
A powerful, extensible dependency injection micro container for JavaScript applications
Refluxjs
A simple library for uni-directional dataflow application architecture inspired by ReactJS Flux
Is.js
Micro check library
Bacon.js
FRP (functional reactive programming) library for Javascript
JS Signals
Custom Event/Messaging system for JavaScript inspired by AS3-Signals