Jailed
Jailed - execute untrusted code with custom permissions
Webshim
Webshims Lib is a modular capability-based polyfill-loading library
Loglevel
Minimal lightweight logging for JavaScript, adding reliable log level methods to wrap any available console.log methods
Node Browserify
browser-side require() the node.js way
Theory
Abstraction layer for cross platform JavaScript.
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
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.
Jwerty
Awesome handling of keyboard events
UI Router
The de-facto solution to flexible routing with nested views
Conditioner
Frizz Free, Environment-aware, JavaScript Modules
Knockout Projections
Knockout.js observable arrays get smarter
Routie
a tiny javascript hash router
Stately.js
Stately.js is a JavaScript based finite-state machine (FSM) engine for Node.js and the browser.
Superagent
Ajax with less suck - (and node.js HTTP client to match)
Contra
Asynchronous flow control with a functional taste to it
Csso
CSS-optimizer