also, a
player class in
MOOs.
Builders are allowed to create things and modify their properties (within the bounds of the permission system of course).
Typically, a builder builds rooms, describes them and populates them with objects: the next step is getting the set of rooms linked to some public area, in order to bask in the warm current of approval that follows.
Or roast in the flames of complaints, depending.
Some builders evolve into programmers.