Paper.js - Open source vector graphics scripting framework that runs on top of the HTML5 Canvas.
VectorWiki - A huge repository of ~120K brand logos in SVG format for free and quick download.
p5.js - JS library for creating graphic and interactive experiences
Brands of the World - Open source database of brands vector logos
Three.js - A JavaScript 3D library which makes WebGL simpler.
BonsaiJS - A lightweight graphics library with an intuitive graphics API and an SVG renderer.