Warp drive is a lightweight jQuery plugin that helps you create a cool, interactive, configurable, HTML5 canvas based warp drive/starfield effect.
Fabric also has SVG-to-canvas (and canvas-to-SVG) parser.
Atrament is a lightweight library that enables the user to draw smooth, natural drawings and handwriting on the HTML canvas.
Vega is a visualization grammar, a declarative format for creating and saving interactive visualization designs.
With Vega you can describe data visualizations in a JSON format, and generate interactive views using either HTML5 Canvas or SVG.
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.
ClassyCountdown is a jQuery plugin that allows you to easily create clean circular countdowns. It is fully customizable and includes 12 themes, which can be modified and it uses HTML5 canvas for rendering the circles.
Particleground is a jQuery plugin for snazzy background particle systems. Particleground includes an optional parallax effect controlled by the mouse on desktop devices and gyroscope on mobile devices.
It works in any browser that supports HTML5 canvas.
waterpipe.js is a jQuery plugin for smoky backgrounds generation (HTML5 Canvas).