The Poser libaries are just directories under Poser. You can't add other libaries but the one Poser has(camera, character, face, hair, light, hand, pose, and props). Under each you may has other directory you create or Other person create for they products like in the character directory you can have "DAZ - People" directory that is create by DAZ went you installed Vicky or Mike. So a environment like builds or sence are props, characters or PZ3 Scene.

The difference between stupidity and genius is that genius has its limits.