Moodle (/ˈmuːdəl/ MOO-dəl) is a free and open-source learning management system written in PHP and distributed under the GNU General Public License.

[8][9][10] Moodle was originally developed by Martin Dougiamas to help educators and scholars create online courses and focus on interaction and collaborative construction of content.

[18][citation needed] Moodle runs without modification on Unix, Linux, FreeBSD, Windows, MacOS and any other systems that support PHP and a database, including web host providers.

In March 2012 Blackboard acquired two companies based on Moodle's software including Baltimore-based Moodlerooms Inc. and NetSpot of Adelaide, Australia.

Dougiamas started a Ph.D. to examine "the use of open source software to support a social constructionist epistemology of teaching and learning within Internet-based communities of reflective inquiry."

[21][22] Other Moodle adopters, such as the Open University in the UK, have pointed out that Learning Management Systems can equally be seen as "relatively pedagogy-neutral".

[30] In the U.S. higher education market as of fall 2021, the top three learning management systems (LMS) by number of institutions were Canvas (30%), Moodle (21%), and Blackboard (20%).

[32] However, by 2017, Moodle had dropped to the third largest provider, due in part to increased adoption of Instructure's semi-open source[33] Canvas platform.