Blackboard
According to Blackboard Inc., "Blackboard.com is a free course Web site creation service that enables instructors to add an online component to traditional classes or teach an entire course on the Web. You can quickly and easily create your own course Web site to bring your learning materials, class discussions and tests online. The service is free, with an enhanced service available for a modest per course fee."
Experimentation with the Blackboard system has been limited as Blackboard Inc. has instituted a fee for all but limited use.