Paper.js — The Swiss Army Knife of Vector Graphics Scripting
Why implement vector graphics on Canvas when you could use SVG?EDIT: Seems to be answered in the FAQ: "We have decided to use the Canvas object as the main backend for now because it is faster than SVG and allows us to implement and optimize our own Scene Graph / Document Object Model. We will be offering SVG (and hopefully PDF) importing and exporting in the future."But it seems hard to believe that doing vector->bitmap rasterization in JavaScript is going to be faster than using the browser's SVG implementation (written in C++).