The game has undergone significant changes to its in-game systems since the initial release of the game back in 2006 and the subsequent closure of the game in 2007. Faction systems, penalty systems, territory control, and many more aspects of the game have been tweaked to ensure proper function and fun for the players involved. However, even with all of these changes, the publisher of the game, Duplex Systems, has stated that things are not as balanced as they wish it to be but they wish to iron out more problems with the help of players in open beta.
If you're interested in the single, persistent universe game, jump on over to the website, sign up for an account, and grab yourself the client.
Update: Nexeon Technologies has clarified that the game is no longer carrying the "Rebirth" subtitle, and is simply called Face of Mankind once again.