Sails
Realtime MVC Framework for Node.js
Stapes
a (really) tiny Javascript MVC microframework
Pegasus
Load data while still loading other scripts and display data faster in jQuery, Backbone, Angular, ... apps
jTypes
jTypes is the most comprehensive and robust JavaScript library for overcoming differential inheritance with prototype-based objects. Its lightweight yet powerful design provides web programmers on any platform or browser the ability to emulate classical inheritance where objects are defined by classes.
Backbone React Component
A bit of nifty glue that automatically plugs your Backbone models and collections into your React components, on the browser and server
Amplify
AmplifyJS is a set of components for data management and application communication.
Tock
Timer Object/Class. Kickass!
P
Peer-to-peer networking with browsers
YUI3
YUI is a free, open source JavaScript and CSS library for building richly interactive web applications.
Nuclear Js
Reactive Flux built with ImmutableJS data structures. Framework agnostic.
Functional Js
A functional js library that facilitates currying and point-free / tacit programming
Terrificjs
Terrific JavaScript Framework
Hinclude
declarative client-side inclusion for the Web
ifvisible.js
Checks if the current page is visible or not
Robotjs
Node.js Desktop Automation.
PreloadJS
PreloadJS makes preloading assets & getting aggregate progress events easier in JavaScript. It uses XHR2 when available, and falls back to tag-based loading when not.
Lips
Scheme based powerful lisp interpreter written in JavaScript