Looks fantastic, Michael. I'm digging the soft specular highlights.

I just want to add that I second Danny's desire to see black surface edges. I thought it would have been a checkbox option or something, but making it available in a config file seems accessible enough. Wouldn't it be more functional to have surface curves black and free standing curves colored according to their style (especially if you add the option to display/alter isoline densities in the future)? Blah, this is probably a discussion that was held earlier on in the forums. I'll look for it. Anyway, great job!