Here's -some- of the things the users came up with:

JCM

ERC

Conformers

Geometry switching

Transmapped hair (bows to the Japanese Poser community, particularly Kozaburo)  

Just about all the goodies we take for granted were created to get around the P4 limitations, and things like conforming clothing were bug exploitations. DAZ didn't think of any of it, neither did Poser's coders. It was the community.

Aaaaah, Ultima Online. Remember when Lord British got nuked? To have had a camera to record Garriot's expression.....