I'm currently using WebGUI and am considering moving to another platform like Drupal. One of the things I really like about WG that I use a lot is the ability to create a variety of User Groups and set the visibility rights of different objects on each page so that any given user can only see things on the page that coincide with the groups to which he belongs. Some places call that "role-based permissions" and other things.
For instance, I use my WG sites to offer product support for several products. There are several distinct groups to which each registered user can belong, and they are able to see/access different things based on their membership. If someone has a license for a "Lite" version of something, then they need to see a download panel that lets them download updates of the "Lite" version. JV Partners will be able to see and access a cross-section of things. Different support forums are present, and while everybody can read any of them, only the ones registered for their particular product version will be able to post to the corresponding forum.
This all comes about by defining specific groups (eg., roles), adding users to various groups, and setting the permissions of each object to allow viewing and/or editing by a specific group.
I was told that Drupal can support this. Can someone point me to some place that documents how this can be accomplished in Drupal? Examples would be helpful, too.