Drawingboard.js
A canvas based drawing app that you can integrate easily on your website.
Soc.js
An easier way to create social icons
jCanvas
A jQuery plugin that makes the HTML5 canvas easy to work with.
Im.js
Image Match - Project to allow compare different images pixel by pixel with good performance
Noisy
A jQuery plugin that adds random noise to the background of a given element.
Gif.js
JavaScript GIF encoding library
Rimg
A responsive image solution for browsers that support mediaqueries. Pure javascript and no server-side code.
Fabric.js
Javascript Canvas Library, SVG-to-Canvas (and canvas-to-SVG) Parser
FloraJS
FloraJS is a JavaScript framework for simulating natural systems in a web browser.
Html2canvas
Screenshots with JavaScript
Isomer
Simple isometric graphics library for HTML5 canvas
Paper.js
The Swiss Army Knife of Vector Graphics Scripting – Scriptographer ported to JavaScript and the browser, using HTML5 Canvas. Created by @juerglehni & @jonathanpuckey
Focal Point
A small set of CSS classnames to help keep images cropped on the focal point for responsive designs. Using only HTML/CSS, web authors can specify an image's focal point, which stays as the image's primary focus, while the image's available width changes on responsive webpages. Crop and re-size images depending on available width and let CSS to do all of the work, and without any JavaScript.
Joint
JavaScript diagramming library
Easel JS
The Easel Javascript library provides a full, hierarchical display list, a core interaction model, and helper classes to make working with the HTML5 Canvas element much easier.
Cropper
A simple jQuery image cropping plugin.
Raphael
JavaScript Vector Library