The question was about the title bar chrome. iTunes positions the traffic light buttons vertically when compact. The Mac App Store app positions them in the center of the title area instead of the top. Quicktime has its own chrome entirely. I'm not complaining about it, just pointing out that non-standard chromes are present on the Mac in Apple's own apps.

Agreed. It probably had more to do with the fact that their store, game details, etc. views were pretty complex. They seem to have solved a lot of that crossplatform pain by implementing most of that stuff using Webkit.

I meant it tongue-in-cheek, but what you say is true and the Steam interface has always been a custom one. I haven't used the Mac version - how did they rectify this on the Mac?