How do I toggle between Tabs in Firefox like Windows Alt+Tab ?
▻https://support.mozilla.org/en-US/questions/955292
(1) In a new tab, type or paste about:config in the address bar and press Enter. Click the button promising to be careful.
(2) In the filter box, type or paste ctrl and pause while the list is filtered
(3) Double-click browser.ctrlTab.previews to set its value to true.
Ça change la vie.