mmoRL is a massively multiplayer online roguelike game. You log in to a central server and play together with other players on the server. The overworld is a safe area and everything there happens in realtime, but the dungeons and other non-safe zones are turn-based and unique per player; you will not find other players in your dungeons. However, in the overworld you can choose to party up with other players, and when you are in a party, you will visit the party leader’s dungeons instead of your own – together with the other players in your party.
The game runs under Windows (.NET) and Linux (Mono). Download it at http://vdzserver.org/games/mmorl.html (only ~100 KB)
(mmoRL is public domain under a CC0 license. See here for details. Long story short, you are free to do whatever you want with the game or its code without any obligations.)