Is it possible to still play 'The Matrix Online'?

Solution 1:

The game is not available to play anymore.

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 March 22, 2005 in the United States. It was released in Europe on April 15, 2005. The game ran continuously from then until it was shut down on July 31, 2009 by Sony Online Entertainment.

Sony Online Entertainment unexpectedly decided to discontinue service to the Matrix Online due to low subscription numbers in June 2009. Sony Online Entertainment shut down the service at 00:00 August 1, 2009. The game had under 500 active players before the shut down.

Solution 2:

There is now:

The Matrix Online Server Emulator (MxoEmu)

While it does not yet allow you to run your own MxO server, it is at least functional.