C++ Raytracer
In about 1990, I wrote a little raytracer in C++ as the course project for a computer graphics class at U. Oregon. About 5000 lines; seemed like a great way to learn the language.
I hate C++.
Anyway, with the help of Julian Kongslie, I got my raytracer up to date and running. It's got some OK reusable classes, and is reasonably fast on a modern box. You can browse or git-clone the source and compile it if you like. The source is BSD licensed.