"The updates will be applied automatically when your Steam client is restarted. The major changes include:

Fixed screen "fuzziness" caused by color correction operation

Fixed text not rendering in game if font Tahoma was disabled

Fixed startup video not playing fullscreen

Added optional -snd_openal command line parameter to force the engine to use the OpenAL api, can be used if Portal is playing no audio when launched normally

Added mac_fsbackground convar, on Snow Leopard or better you can set this to have Portal still visible when it is not the foreground application"

Valve also announced the Mac Civilization IV steamplay versions are available now:

"Previous PC Owners of Civilization IV Games on Steam Get Mac Version
Yesterday when we shipped Steam on the Mac, previous owners of the PC Steam version of Sid Meier's Civilization IV, Civilization IV: Beyond the Sword, Civilization IV: Warlords, Sid Meier's Civilization IV: Colonization, or Sid Meier's Civilization IV: The Complete Edition did not have access to their games when logging in on a Mac.

But as of now, upon logging into Steam, those owners will have access to the Mac version of their games, right in their Steam library."

• Quick Look: Mac OS X Portal Performance (Performance and Image Quality comparisons vs Windows version using a Hackintosh Core i7 @3.3GHz w/GTX-285 system.)
• Hands-on with Steam gaming on four different Macs
• Browse the current Mac Games on Steam (64 listings as of launch day - Torchlight has an intro 50% off price, and there's some game bundle offers.)
• The Steam Mac Games Watchlist

I added note to yesterday's post about Steam not working with "Case Sensitive" OS X disk format, although I (nor most OS X users I suspect) have never used that format option personally. And one mac owner at MU noted problems due to some (duplicate?) fonts installed by an older version of MS Office (requiring deleting the duplicate fonts). Of course like any software (especially v1.0) some have had other problems.
And saw several posts from users upset over problems such as "steam servers too busy" to allow playing a game. (Something I've seen dozens of times in the past - and with a big increase in downloads recently (from Macs as well as the free Portal offer for both platforms), that's not surprising.)
I've not tried offline mode yet on the Mac, but for single-player steam games you can restart Steam in offline mode to play, although in my experience you also need to disconnect from the internet as well. Otherwise I'd see steam games quit with "no steam logon" errors if a net connection was still enabled. (And personally I've always unchecked the option to load Steam at startup in either OS.)

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