RenderPixie

An open-source RenderMan. Ooooh. Do want.

MathBox

Another in-depth article from Steve Wittens, about animation, GL, and JavaScript.

Nice mathematically based graphics

I give you Ogre's gallery.

SmallVCM

A small renderer for 3D scenes using a variety of different algorithms.

The Construct

A pretty big name for a C++ library that does pretty cool stuff in terms of the math of simulation.

Learning Modern 3D Graphics Programming

An excellent C++/OpenGL-based tutorial, as yet unfinished.