Im.js
Image Match - Project to allow compare different images pixel by pixel with good performance
Rimg
A responsive image solution for browsers that support mediaqueries. Pure javascript and no server-side code.
Liquidfun
2D physics engine for games
Obelisk.js
JavaScript Engine for Building Isometric Pixel Element with HTML5 Canvas
Jcrop
Jcrop (official) - Image Cropping Plugin for jQuery
P5.js
A JS client-side library for creating graphic and interactive experiences, based on the core principles of Processing. http://twitter.com/p5xjs —
Ocanvas
JavaScript library for object-based canvas drawing.
Color
JavaScript color conversion and manipulation library
Gif.js
JavaScript GIF encoding library
Soc.js
An easier way to create social icons
Img to Ascii
A JavaScript implementation of a image to Ascii code
Breathing Halftone
Images go whoa with lots of floaty dots
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.
Mapmap.js
A data-driven API for interactive thematic maps
Paper.js
The Swiss Army Knife of Vector Graphics Scripting – Scriptographer ported to JavaScript and the browser, using HTML5 Canvas. Created by @juerglehni & @jonathanpuckey
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.
Html2canvas
Screenshots with JavaScript