Simon
I think there are a lot of lurkers, don't know why they never reply, maybe shy students, who knows.
The other supported renders are Mental Ray and any renderman complient renderer.
we use Mantra only, but we are a small shop with very limited budget. When you get a class renderer like mantra for free with pretty much unlimited render licenses you don't worry about any others. But for the big boys Renderman is usually the only choice I think, mantra too for the same reason as us, it's there it's good and it's free.
Could you elaborate on “renderman compliant renderer”? From what I understand, RenderMan is not an actuall renderer but a tool that tells a “renderer” how and what to render, is this correct?