A site which might be of interest is bugle4d, a 4d wireframe rendering engine. The code and such on that site is completely out of date.
I have recently written working wireframe rendering code- I really wanted to get it off my back. Theres a few more things I'll do, adding a camera and perhaps other stuff, but bugle4d is essentially done.
When its done, I'll put it into GPL, and place it on the site.

After that, I'm considering taking bugle4d and writing a n-d rendering engine. It should not be hard to do with the absolutely lovely design I've done.
Perhaps even threading it.

I've a plan to start updating this site with a completely {nerdy|non-nerdy} topic soon- within a month. Yay!