Shade will open a pz3 with no problem, I've done it a few times :)  I cant say it's the easiest tool for manipulating meshes though, though it may be i need more practise :)

I dont think it will export in the pz3 format though, but then the render engine in shade is great I have used it alot.  You have to do some work on the materials exported from poser though.

John

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