Egjs
Set of UI interactions, effects and utilities components library using jQuery.
Transparency
Transparency is a semantic template engine for the browser. It maps JSON objects to DOM elements by id, class and data-bind attributes.
Humane.js
A simple, modern, browser notification system
Weld
Template antimatter for Node.js (Browsers too!)
Knockout Projections
Knockout.js observable arrays get smarter
Serenade.js
Client side MVC framework
Swig
Take a swig of the best template engine for JavaScript.
Sammy
Sammy is a tiny javascript framework built on top of jQuery, It's RESTful Evented Javascript.
Jsface
Small, fast, elegant, powerful, and cross platform JavaScript OOP library. Support main(), singleton, super call, private, mixins, plugins, AOP and more.
Davis.js
RESTful degradable JavaScript routing using pushState
Backbone Marionette
Make your Backbone.js apps dance with a composite application architecture!
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.
Tock
Timer Object/Class. Kickass!
Kefir
A Reactive Programming library for JavaScript
Simulacra
One-way data binding for web applications.
Knockout
Knockout makes it easier to create rich, responsive UIs with JavaScript