Some time ago, I wrote an n-dimensional raytracer in C++. It does a fair number of things, none of them efficiently, most of the rigidly.
There are a bunch of things that I wanted to do with it for a long time, but it’s been too slow and rigid to make any of those things fun.
Enter Lisp. As soon as it made it through my skull that Lisp is actually compiled (honest-to-goodness your-CPU instructions), I wanted to rewrite the whole thing in Lisp. I have finally gotten started on doing that. And, I just made it to the point where I’m actually tracing rays. Here is a stereo pair of a three-dimensional scene: