Beautiful, this must have been an excellent learning experience to make.
I've done some very basic rendering code in C from a rendering internals course, and at the same time I'm learning about perspective from the drawing/art side. I wonder how much learning one would help the other, in a practical way.
The author is a world renowned expert in 3D graphics.
I see, it looks like he's the one behind ThreeJS. Well, he had to make ThreeJS before he could make this, and that must have been a learning experience, right? :D