All this has culminated in a rather successful thrust to build a comparatively fast raytracer in Epoch. The feature set is pretty limited (one sphere lit by a single light source) but the code is simple enough and the results are satisfactory. I can run a 600x600 pixel scene at about 16-17 FPS on my development laptop, which makes me very very happy. (Keep in mind that at the beginning of this enterprise, the same image at 300x300 was taking 8 seconds to render.)
If I get the energy over the next couple of days, I'm going to write up a wiki article with a development postmortem and maybe shove it around the internet a little bit and see what people think. In the meantime, consider it a tasty reward for following my GDNet journal.
Here's the download: Epoch Realtime Raytracer Demo
Grab it, give it a shot, let me know how well it runs! (Just beware the really nasty pauses that happen when the garbage collector fires.)