Originally planned for Firefox 3.0 and 3.5 but finally backed out in both development cycles, tab preview is available again in Firefox 3.6 alpha 1 nightlies to provide visual tab switching: you press Ctrl + Tab to get previews of the current along with the five most recently used tabs, plus an option to show all tabs’ thumbnails.
The all tabs preview includes a search bar to look for keywords among tab titles and tab close buttons for some housekeeping.
Also back is the new behavior for single Ctrl + Tab:Â instead of moving to the next tab in the tab bar, you switch to the previously used tab.
Unlike previous attempts, this time tab preview and the new tab switching behavior are off by default. To enable tab preview, set browser.ctrlTab.previews to true via about:config. For the new behavior, set browser.ctrlTab.mostRecentlyUsed to true.
It’s also worth mentioning that the list all tabs button still shows a list of tabs, while recently released mockups and previous implementations in Firefox 3.0 and 3.5 replaced it with a tab preview button. These just could be temporary and a tab preview button could be on its way.
While it definitely looks good and modern (it still has to undergo Windows and Linux theming, and I would prefer Flip 3D on Vista and 7), I’m still not convinced on how much it will improve tab switching for heavy tab users like myself (usually 20+ tabs), but at the very least, I find more helpful than the current combination of tab bar scroll bars and a list.