Enyo
A JavaScript application framework emphasizing modularity and encapsulation
Backbone Deep Model
Improved support for models with nested attributes.
Mobx
Simple, scalable state management.
Routie
a tiny javascript hash router
JavascriptMVC
Develop with direction! With CanJS, jQuery++, FuncUnit, Steal, DocumentJS.
Lazyload
Tiny, dependency-free async JavaScript and CSS loader.
Weld
Template antimatter for Node.js (Browsers too!)
Prime
an OOP javascript library for node.js and the browsers
Tweet
put twitter on your website with tweet, an unobtrusive javascript plugin for jquery
Sticky Kit
A jQuery plugin for creating smart sticky elements
Queue
Yet another asynchronous helper library for JavaScript. 387 bytes minified and gzipped!
Gas
Google Analytics on Steroids. A Google Analytics implementation with more power features.
Egjs
Set of UI interactions, effects and utilities components library using jQuery.
Componentjs
ComponentJS -- Powerful run-time Component System for structuring HTML5-based Rich Clients
Cycle Core
A fully reactive JavaScript framework for Human-Computer Interaction
Knockout Projections
Knockout.js observable arrays get smarter
Kefir
A Reactive Programming library for JavaScript