The Matrix Online was a MMORPG that was made by Warner Bros. Entertainment and Monolith and was later bought out by SOE. It began beta testing in June 2004 and went live in March 2005 for North American users, and April 2005 for European users. It was eventually shut down in July of 2009, due to low sales.
The Matrix was unique in the MMO market for two major reasons: First, was the leveling and skill system. Unlike standard MMO's, where you pick a class and then delve into specializations within that class, The Matrix had a modular system that gave every player access to all of the skills, but only allowed them to pick a certain number of skills in a certain progression at a time. This allowed characters to make unique classes by mixing and matching abilities and weapons and was fairly intuitive despite sounding incredibly complex.
Second, was the Live Events. Unlike other MMO events, this one had a specific team designed to act out the roles of the minor characters and contacts during a event.
The story of MxO was as such: After the death of Neo, theMachines andZion have stopped engaging in open warfare and now fight a cold war in the Matrix proper. TheExiles, led by theMerovingian, also joined in the fray, recruiting redpills (PC's) to do their dirty work. The major arcs in the story included the death of Morpheus, illegal codes that turned some redpills intoSuper Soldiers, a conspiracy to kill everyone byholding a free concert, and finally giving everyoneGM level powers.
As stated above, the game is now defunct. A sideshow is available at the community website,Data Node One.