Valve Software has been teasing a Mac version of the Steam gaming platform for a while now, and that day has finally arrived. Realizing that a free gaming platform upon which you own no games isn't the most exciting thing in the world, Valve has sweetened the pot a bit by giving away Portal on both Mac & PC through May 24th.
For the uninitiated, here's what you need to know. Portal is an absolute must. Quick synopsis: you are a test subject forced to traverse a series of (excellent) puzzle rooms. Your guide is a monstrously indifferent and possibly murderous AI named GLaDOS. There are wormholes (and a wormhole gun!). The cake is a ... bzzzt. End transmission.