I think that's just the official name that it goes by. I'm taking that from Seno's web site. AND if you do know of Eve Phantast, do you know the differences between the two?

my 2 cents.... I found that the Pro Pack is much slower than P4 on my Mac OS 9.1. Also, Poser 4 and Quicktime 6 don't play nice. I can do my work and even render, but after the animation is done, when I close the window, it freezes. If you're stuck on an old system like mine, I'd vote for P4. I started with Poser 1, wayyyy back in the 90s, and I think P4 is just as resposive and flaw free as the best of em. No crashes ever.