The first clue came from the official message boards for Tripwire Interactive's zombie shooter as a desktop screenshot posted by a Tripwire team member (shown above) seemed to show the game running natively on a Mac OS. There are also hints from other Tripwire team members in the forums that a Mac port was in development.
However Tripwire's president John Gibson officially confirmed to Big Download today that both Red Orchestra and Killing Floor would indeed be released for the Mac. In addition to the regular games, the Mac ports will have access to all of the downloadable content available for both titles. They will also have Steam achievements and cross-platform multiplayer with their PC counterparts. An exact release date for the Mac ports has not been revealed but Gibson told us it should happen around the time the Mac Steam client is officially available or soon afterward.
Gallery: Killing Floor