I have a Mac Pro and I would like to idle on TF2. The problem is that there is no toolbar so I can't get out of TF2 unless I disconnect from the server I'm on and I quit TF2. I would like to know how to get the border/toolbar on the window.
To get TF2 in a window:
- From the main menu, click Options and then the Video tab.
- Change the Display mode setting to Run in a window.
- You will probably also want to set the Resolution (which will now control the window size) to something smaller than your actual screen size so that the window fits nicely.
- Click OK or Apply.
As noted in comments, you can also use Command-Tab to switch away and leave TF2 running in the background, instead of using windowed mode.
(Information that might be useful context for curious readers from other platforms: There are about three different ways of implementing full-screen on Mac OS X, and a lot of games use an older one that defaults to leaving Command-Tab non-functional. Luckily, TF2 does support it.)