Poser 4 itself does not have the SWF export - you'll need the ProPack in additon to that. Poser 5 comes with SWF export, and considering the price (compared to P4+PP) and feature set of P5 over P4+PP, I'd go with Poser 5 if I were you. The latest SR killed many stability issues, and once you played in the material room for an hour you wonder how you could ever live without it.