Loglevel
Minimal lightweight logging for JavaScript, adding reliable log level methods to wrap any available console.log methods
Jquerypp
jQuery's missing utils and special events
Backbone Nested
A plugin to make Backbone.js keep track of nested attributes.
Simplate
A simple, but powerful, templating engine for JavaScript.
Tweet
put twitter on your website with tweet, an unobtrusive javascript plugin for jquery
Query Loader2
Version of the QueryLoader by Gaya Design. Preload images with ease.
Nuclear Js
Reactive Flux built with ImmutableJS data structures. Framework agnostic.
Js Cache
jsCache is a javascript library that enables caching of javascripts, css-stylesheets and images using my localStorage polyfill. This is especially useful when serving your website for mobile phones, which have limited HTTP caching available, but also speeds up your site in an ordinary web browser as it saves HTTP requests and loads all files asynchronously.
Eve.js
A <3kb JavaScript file providing three simple methods to organize code into CSS namespaces which magically restrict code to the current context, allowing for dramatic reductions to code size and development time.
Optics
Profunctor implementation of Lenses, Prisms, Traversals, Isos, etc.
Muuri
Responsive, sortable, filterable and draggable grid layouts
Min Pub Sub
198 byte publish/subscribe messaging micro-framework
Maria
The MVC framework for JavaScript applications. The real MVC. The Smalltalk MVC. The Gang of Four MVC.
JayData
JayData is a unified data access library for JavaScript to CRUD data from different sources like WebSQL/SQLite, IndexedDB, MongoDb, ASP.NET WebAPI, OData, HTML5 localStorage, Facebook or YQL. The library can be integrated with KendoUI, Knockout.js, Handlebars.js or Sencha Touch 2 and can be used on Node.js as well.
Canjs
Can do JS, better, faster, easier.
Highway
A fast, lightweight and simple Javascript routing library with no dependencies.
Nunjucks
A jinja2-inspired templating system for javascript