Just to be real picky, Pixar Renderman (PRman) is a render system ($$$$) from Pixar, used in such films as "Finding Nemo". And yea it's a world standard but it's definitely not Poser's Firefly renderer. What I think Maxx meant to say is that it's Renderman compliant but that's not a render system but a technical specification for interfacing between modeling and rendering programs (http://www.renderman.org/). I'm not sure that Firefly is even that, although one could say that since Poser exports to RIB that it is. As mentioned Firefly is the old version of a renderer offered by Pixels3D and most of the Pixel3d images are done with the newer version, which I think is a vast improvement over the old one, both in speed and features - especially greatly improved displacements, better refraction (which is rather poor in Firefly) and quasi radiosity. My biggest problem with RMan render systems is that most of them use the Pixar REYES render engine (circa 1984) that was primarily designed for animations and which sacrifice accuracy (not quality!) for speed (like soft shadow mapping which is a 2D blur effect). They don't do refraction,GI,HDRI,etc and only reflect a single "enviroment" image. For these they need to add in a raytracer on top of the REYES engine. Cornel raytracers (like Bryce and Vue) use models of real world physics (soft shadows are created by taking the standard "point" light and added up to 256 clone lights around it, which creates a much more realistic effect albeit much slower) which I greatly prefer. Best; Dan