You probably know that you can cycle the windows of the frontmost application by pressing Command-` (lower-case tilde), and that you can cycle them in the opposite direction by adding Shift to the mix. But what if you want to cycle between the open windows in all applications? One solution is Witch, which displays a pop-up menu of open windows when you press Option-Tab. (Dan Frakes covered Witch in this Mac Gems writeup last year if you’d like to find out more about it. One of Witch’s advantages is that it can also access minimized windows.)
Another solution is to use Exposé, which sort of provides a solution. Press F9 to invoke Exposé, then press Tab and Shift-Tab to cycle between running programs’ windows. This solution, however, doesn’t provide direct access to every window in a given program; instead, it brings them all up as a unit. So here’s another built-in solution that will provide access to every non-minimized window that you have open: use Keyboard Navigation.
If you’re not familiar with it, Keyboard Navigation is a feature of OS X that makes most, but not quite all, of the OS X interface navigable using just the keyboard. You can see the default settings for Keyboard Navigation on the Keyboard Shortcuts tab of the Keyboard & Mouse System Preferences panel:
If you’ve never used Keyboard Navigation before, you may notice that the first few options in this section are grayed out. That’s because you have to enable full keyboard access, which you can do by pressing Control-F1. (Note that if you’re using a laptop, you may have to press Fn-Control-F1, depending on how you have your function keys set up.) Once enabled, you can now use the listed shortcuts, including Control-F4 (and Shift-Control-F4) to cycle between open windows in all applications.
As you can see from the other shortcuts, you can activate a number of other screen areas via the keyboard, too. Press Control-F2 to activate the menu bar, and you can then type menu commands’ first letters (or use the arrow keys) to activate the specific menu item you’re interested in using. Control-F3 will activate the Dock, and you can then use the arrow keys and the Enter key to select and activate specific items within it. (You can also press H to hide and Q to quit the highlighted app; these same keys also work in the Command-Tab application switcher.)
Keep in mind that you’re not stuck with the keyboard shortcuts Apple has assigned—just double-click on the entry in the Shortcut column for the command whose shortcut you’d like to change. On my Mac, for instance, I changed Control-F4 to Command-Control-`, so it’s quite similar to the existing Command-` shortcut for cycling windows within an application. If you ever want to get back to Apple’s settings, just click the Restore Defaults button.
So there you have it—not one, not two, but three distinct ways to cycle between all open windows on your machine. I personally prefer Witch, though I use the other two methods at times as well.