Not all browsers support stack traces on error objects, but TraceKit squeezes out as much useful information as possible and normalizes it.

This is a collection of JavaScript wizardry that can shave bytes off of your code.

freedom.js is a framework for building peer-to-peer (P2P) web apps. Easily create social applications that work in modern web browsers, Chrome packaged apps, Firefox extensions, node.js, and native mobile apps. freedom.js apps are just JavaScript, so they can be distributed as packages on an app store or hosted on static web servers. We're bringing peer-to-peer back, baby.

Shariff enables website users to share their favorite content without compromising their privacy.

Flocking is a JavaScript audio synthesis framework designed for artists and musicians who are building creative and experimental Web-based sound projects.

Fast, JavaScript DSP library that creates JIT optimized audio callbacks using code generation techniques.
It is designed to be a fast audio API for browser based audio content.

Apache CouchDB™ is a database
that uses JSON for documents,
JavaScript for MapReduce indexes,
and regular HTTP for its API

Babel will turn your ES6+ code into ES5 friendly code, so you can start using it right now without waiting for browser support.

Beautiful transformable icons
built for the web.

JavaScript crusher, code minification

RegPack is a packer intended for use on minified Javascript code.
It is mostly suited to small size constraints (1kb, up to 4kb).

An interface for the Web Audio API that supports rhythms, multiple instruments, repeating sections, and complex time signatures.

DEFENDER of the favicon is a JavaScript remake of Eugene Jarvis' brilliant arcade game Defender written by Mathieu 'p01' Henri and inspired by Scott Schiller's experiment with generated favicons VU meter. The idea was to push the concept of generated favicons further and pack a thrilling retro shooter in 16×16 pixels using JavaScript, canvas and data: URIs.

D3.js is a JavaScript library for manipulating documents based on data. D3 helps you bring data to life using HTML, SVG and CSS. D3’s emphasis on web standards gives you the full capabilities of modern browsers without tying yourself to a proprietary framework, combining powerful visualization components and a data-driven approach to DOM manipulation.

Rickshaw is a JavaScript toolkit for creating interactive time series graphs.

A javascript date library for parsing, validating, manipulating, and formatting dates.

localForage is a handy library that improves the offline experience of your web app by using asynchronous storage (via IndexedDB or WebSQL where available) but with a simple, localStorage-like API.

jscs is a code style checker. jscs can check cases, which are not implemented in jshint, but it does not duplicate jshint functionality, so you should use jscs and jshint together.

This is JSHint, a tool that helps to detect errors and potential problems in your JavaScript code.

polyfill makes web development less frustrating by selectively polyfilling just what the browser needs. Use it on your own site, or as a service.