Valve have released the following parody of Apple's 1984 Macintosh commercial in order to promote the release of Half-Life 2 for Mac. Half-Life 2 is one of the top-rated and best-selling games of all time so it is an obvious choice when Valve was considering what game to release next. This is in line with Valve's policy of releasing a major game every week for OSX users. New games will be released on Steam for OS X on Wednesdays in the coming weeks which Valve says will "highlight specific functionalities of Steam on the Mac"
Original Macintosh advert: