I see that there is a [https://support.mozilla.com/en-US/kb/Keyboard+shortcuts keyboard shortcut] for switching tabs within a Firefox browser window, but I'd also like one for switching between browser windows. I imagine this is easier on Windows, where each browser window sort of behaves as a separate application, but on the Mac OS an application can own several windows. Thus, the OS doesn't provide support for switching between browser windows via a keyboard shortcut; it can just switch between applications, which brings '''all''' of the target application's windows to the front.