Sorry for the bad formatting, apparently I cannot edit my comment on HN anymore. 1. Go to System Settings -> Keyboard -> Keyboard Shortcuts -> App Shortcuts

Sorry for the bad formatting, apparently I cannot edit my comment on HN anymore. 1. Go to System Settings -> Keyboard -> Keyboard Shortcuts -> App Shortcuts 2. Click the small (+) button under the shortcuts table 3. Choose/Type the following values in the modal: - Application: All Applications - Menu Title: Zoom - Keyboard shortcut: Command + Shift + M (My preferred shortcut) 4. Click Save. 5. Voila, now you are able to maximize any window, and pressing it again it goes back to its original size. A cool trick is that now if you hover the green (+) button on the top of any page you will be able to access that shortcut from there as well. It sits just under the "Enter Full Screen" menu option.