I checked this site, http://www.freeciv.org/ , some months ago. It seemed to have a cool Civ clone for Unix. Several variants of *ix were supported, but Windows only through some uber-geeky tricks, basically running a unix emulator under windows. There was mention of a native Windows port, but it wasn't there.
Now it is there, and I am impressed. Nay, awed, humbled before the monumental work of art. It is definitely worth more than I gave for it (yes, it is free). It is inherently multiplayer, though you'll need some kind of network if you run Windows, as Windows does not support multiple instances of the client.
Do you believe it automatically detected that my Windows use Norwegian settings, and installed the game with Norwegian text? And my tiny Viking empire even flies the genuine Norwegian flag ...
Either some people have too much time on their hands, or they are ethically superior. Wow again.