Slight adjustments for Renderman compliant renderrers may be necessary, I often had to adjust texture paths when using BMRT or 3Delight. Yes, you can use it to export animations to Pixar's PRMan, it has been a feature since Poser 1. However, it has less relevance with Poser 5 now: FireFly is a REYES renderer like PRMan and has also a very flexible material system with almost similar features. If you don't want to use distributed rendering or write your own shader nodes in the Renderman shading language, there's hardly anything PRMan will do for you that FireFly couldn't (for much less money).