moodle open source course management system

Moodle is a course management system (CMS) - a free, Open Source software package designed using sound pedagogical principles , to help educators create effective online learning communities. You can download and use it on any computer you have handy (including webhosts), yet it can scale from a single-teacher site to a 50,000-student University. This site itself is created using Moodle, so check out the Moodle Demonstration Courses or read the latest Moodle Buzz.