http://php.opensourcecms.com/scripts...p?scriptid=191
You can try a demo of Drupal here. Just log in to the admin page. The password and login is mentioned on the page. Should give some information on how it works.
I had to test it myself for a school project last thursday. Its kind of a complicated and it takes time to learn, or thats what I've said to my teacher when he asked my opinion of it.