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.

Sylvester is a JavaScript library designed to let you do mathematics with vectors and matrices without having to write lots of loops and throw piles of arrays around. It includes classes for modelling vectors and matrices in any number of dimensions, and for modelling infinite lines and planes in 3-dimensional space. It lets you write object-oriented easy-to-read code that mirrors the maths it represents.