There are many libraries out there. However, i would advice to consider option with Fabric.js, Cake.js, Doodle.js and KineticJS .
Fabric.js is a far more feature rich offering than jCanvaScript. Included in the hefty download file is an SVG-to-canvas parser, unit testing and even limited IE support through Explorer Canvas.
Unlike most of the libraries available in the market, CAKE actually has a number of comprehensive online tutorials. It is important to say that it is written by Matthew Casperson and cover both a basic introduction and more complex animation.
However, there is a KineticJS which i did not try yet. According to there web sites:
You can draw things on the stage and then add event listeners to them, move them, scale them, and rotate them independently from other shapes to support high performance animations and transitions. Served hot with a side of awesomeness.
In conclusion, i would advice to look at specific scenarios (the common requirements and project needs) where each of this libraries may do the required job.