Moodle is a Course Management System (CMS), also known as a Learning Management System (LMS) or a Virtual Learning Environment (VLE). It is a Free web application that educators can use to create effective online learning sites.
Just because you're online doesn't mean that you can't experience the world first-hand - or as close to first-hand as possible. Here are websites that feature virtual learning experiences, exposing online visitors to everything from history to geography, astronomy to anatomy, literature to government.