Civilization V will officially be released for the Mac platform on Tuesday via publisher
Aspyr but until today it was unknown if the Mac port of the turn-based strategy game would support Valve's
SteamPlay feature. Today Aspyr confirmed that thanks to user feedback the Mac port will indeed support SteamPlay. That means people who purchased the PC version will be able download the Mac port for free and vice versa.
Aspyr explained its decision by saying, "From the comments that poured in, it seemed clear that many of you had purchased the PC version, even though it was the Mac version that you really wanted, and either expected that
Civ V Mac would support SteamPlay or that
Civ V Mac would not even be released for some time." The Mac version will be made available on Steam and other download sites as planned on Tuesday.
Other aspects of the Mac port are detailed in the blog post including world that SteamCloud game save support would be coming sometime after the game's release. Unfortunately there will be no Mac demo of the game nor any support for mod tools for the Mac version.