It's the leading open source learning management system in the world. It provides 100s of 1000s (millions?) of students and teachers, learners and educators a means of collaborating, engaging content and organizing studies online. It's easy to tout the great things that Moodle has done for education in the dozen short years since it was created by Martin Dougiamas. It has certainly created and standardized the base-level of learning management systems available to schools throughout the world. Despite budget cuts and cost saving measures, Moodle can be installed and released to teachers with minimal resources. The locomotive that is Moodle is tearing down boundaries of accessibility to technology in the world of education, and that's a great thing.