Cities XL is a new
Sim-City style game that you play online with other players. It's definitely the first city building without war game that I've played. There are games like
King's Age,
Tribal Wars, and
Ikariam where you do city building, but you've always got war to deal with. In
Cities XL, the focus is on building your city, taking care of the citizen's needs, and growing in accordance with those needs. In that way, it's the first MMO I've played like it. You get to work on your own city independently of what others are doing, but you can still talk to the other players and trade with them. It makes it so that you can play at your leisure without worrying that someone is going to kill you while you sleep, but you still get the benefit of having other people to talk to.