Wow! Several members of the Gwydion Dylan team are participating in the ICFP Programming Contest this year. They're cranking out 3D-rendering code at an impressive rate.
Unfortunately, my girlfriend leaves for college in a few days, so I can't participate in a 72-hour sleepless hacking run. I've offered to beat d2c's optimizer with a cluestick, if necessary, since nobody on the contest team will have time to figure out my documentation on high-speed collection types. (My code is basically a hack--it uses some hand-coded type substitutions instead of a fully general template model.)