Scene Graph.js
HTML5 Canvas and Animation Framework
Comic.js
Cartoon style drawing for HTML5 Canvas & Raphael.js & D3.js & SVG.js
Drawingboard.js
A canvas based drawing app that you can integrate easily on your website.
Im.js
Image Match - Project to allow compare different images pixel by pixel with good performance
Kinetic Js
KineticJS is an HTML5 Canvas JavaScript library that extends the 2D context by enabling canvas interactivity for desktop and mobile applications.
Soc.js
An easier way to create social icons
Cropper
A simple jQuery image cropping plugin.
Paper.js
The Swiss Army Knife of Vector Graphics Scripting – Scriptographer ported to JavaScript and the browser, using HTML5 Canvas. Created by @juerglehni & @jonathanpuckey
Joint
JavaScript diagramming library
Noisy
A jQuery plugin that adds random noise to the background of a given element.
Img to Ascii
A JavaScript implementation of a image to Ascii code
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.
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.
Isomer
Simple isometric graphics library for HTML5 canvas
Html2canvas
Screenshots with JavaScript
jQuery QR Code
qrcode generation standalone (doesn't depend on external services)
Jcrop
Jcrop (official) - Image Cropping Plugin for jQuery