The Matrix Online (also known as MxO) is a massively multiplayer online game eveloped by Monolith Productions. It is an official continuation of the The Matrix storyline. The game began closed beta-testing in June 2004 which was then opened for people who pre-ordered the game in November 2004. Warner Bros. and Sega officially released MxO on 22 March 2005 in the United States. It was released in Europe on April 15, 2005.