Moodle is a classroom on the web. Essentially it is designed for organizations or individuals who want to teach, offer courses, test their students, offer grading, allow for student interaction, and much more. This is a complete out-of-the-box solution for any educational or testing Endeavour.
The Beauty of Open Source – My top 5 picks. I also suggest other software like Joomla, Drupal, PHPCoin, GIMP, LINUX, and many more. I plan to write more about these in the future but I wanted to mention the top 5 Open Source programs that I use most.