"The main focus of CamanJS is manipulating images using the HTML5 canvas and Javascript. It's a combination of a simple-to-use interface with advanced and efficient image/canvas editing techniques. It is also completely library independent and can be safely used next to jQuery, YUI, Scriptaculous, MooTools, etc."

"Typed Arrays can significantly increase the pixel manipulation performance of your HTML5 2D canvas Web apps. This is of particular importance to developers looking to use HTML5 for making browser-based games."

"Fabric.js is a framework that makes it easy to work with HTML5 canvas element. It is an interactive object model on top of canvas element. It is also an SVG-to-canvas (and canvas-to-SVG) parser.

Using Fabric.js, you can create and populate objects on canvas; objects like simple geometrical shapes — rectangles, circles, ellipses, polygons, or more complex shapes consisting of hundreds or thousands of simple paths. You can then scale, move, and rotate these objects with the mouse; modify their properties — color, transparency, z-index, etc. You can also manipulate these objects altogether — grouping them with a simple mouse selection.

You can add text on canvas and dynamically manipulate its size, alignment, fontfamily and other properties. You can apply filters to images, making them grayscale or removing background. You can serialize the entire canvas into a JSON string — saving it locally or on a server — then completely restore it at any time. You can also export canvas data back into SVG at any time."

"Paper.js is an open source vector graphics scripting framework that runs on top of the HTML5 Canvas. It offers a clean Scene Graph / Document Object Model and a lot of powerful functionality to create and work with vector graphics and bezier curves, all neatly wrapped up in a well designed, consistent and clean programming interface.

Paper.js is based on and largely compatible with Scriptographer, a scripting environment for Adobe Illustrator with an active community of scripters and more than 10 years of development.

Paper.js is developed by Jürg Lehni & Jonathan Puckey, and distributed under the permissive MIT License."

Very cool, render PDFs natively with JavaScript and HTML5 (Work in progress)

"This is an implementation of the Knuth and Plass line breaking algorithm using JavaScript and the HTML5 canvas element. The goal of this implementation is to optimally set justified text in the new HTML5 canvas element, and ultimately provide a library for various line breaking algorithms in JavaScript."

EaselJS is a JavaScript library that allows you to work with the Canvas element in ActionScript style.

This is so awesome it makes my brain explode.

"Raphaël is a small JavaScript library that should simplify your work with vector graphics on the web. If you want to create your own specific chart or image crop and rotate widget, for example, you can achieve it simply and easily with this library."