Two.js is a drawing API that can render using canvas, WebGL and SVG.

Two.js uses Underscore.js and Backbone.js for event handling. While not supporting text and images, Two.js instead focuses on the vector+shape side and altogether makes for a great tool for creating animations with shapes.

It has many methods for handling vectors, polygons and their groups.

Pixi.js is a lightweight 2d rendering engine which supports a vast scale of devices.

Pixi.js allows users to employ the power of hardware acceleration without having to know WebGL.

It can currently function as a WebGL renderer and a canvas renderer; it also has an easy to use API and support for mouse and multi-touch interaction. Pixi.js also has an extensive documentation that sheds light on what the framework can do.

Headtrackr is a JS library for real-time head and face tracking.

Headtrackr works as a canvas element which copies the frames from an initiated video. Once initialized, the library generates face detection events all over the place, and this is where your app intercepts them.

A demo says more than a thousand words: check out a neat little game you can play with your head!

jQuery.BlackAndWhite is a plugin for converting colored pictures to greyscale. 

You can use the plugin inside image galleries to achieve a chic effect, as in the picture the highlighted images is in color so it stands out.

The plugin uses HTML5′s canvas tag, but includes a fallback for older browsers as well.

OSM Buildings is a JS library for visualizing 3D building geometry.

OSM Buildings uses 2D Canvas operations, thus no WebGL support is required.

You’d use this type of library for visualizing cities, but it could probably be used to visualize terrain irregularities as well. Currently OSM building projects are available for Paris, Moscow, London and other cities, mostly European.

Canvas Query is a wrapper library that allows using the canvas element with a syntax akin to that of jQuery.

It also adds numerous image manipulation methods for game developers.

The main advantages to using this library are the addition of jQuery’s chaining methods and color/layering options that make creating things on the canvas element much easier.