BuddyPress.org

We want to explain how we have used BuddyPress and some useful WordPress plugins to configure a basic but fully functional online campus for a single course with multiple subjects.
The campus we need will have a public zone for visitors, and a private, password protected zone where teachers and students are able to collaborate in a controlled, structured and easy way.

http://www.rubiomarin.com/en/2011/09/01/how-to-create-a-private-online-campus-with-buddypress/