Yes it is. You need the Steam application to download it.
It will be on Mac the day Portal 2 is released.
no pc and mac only
You can buy Portal from Steam. Portal was free on many occasions but it is currently a paid product.
Buy it through steam.
A wide variety of games, available from the Mac's built in App Store, Steam and numerous other sources can be played on a Mac. Current popular games include Assassins Creed, Portal 2, Civilization V, Iron Marauders etc. etc.
Portal is not currently available on any emulated systems.
ps3, Xbox 360, PC/MAC
PC, PS3, XBOX 360, Mac,
No. Portal 2 is available on XBOX 360, PS3 and PC only.
No, they just make it for PS3, XBOX 360 and PC/MAC.
If you want to play the game on a PC or a Mac, yes.
Portal 2 requires an up to date version of Snow Leopard. The requirements are:OS: MAC OS X 10.6.7 or higherProcessor: Intel Core Duo Processor (2GHz or better)Memory: 2GB