More Opera behaviour I was missing in Firefox:
- Focus Last Selected Tab 0.8.1
Brings focus to the last selected tab when closing the active tab. Focus previous tab by clicking the active tab. - Tabbrowser Extensions 1.11.2004111302
Add-on package for extending operations of tabbed browsing; e.g., tabs become re-ordable by drag and drop; undo tab close; suppress
referer; … etc. Although I haven’t been able to drag and drop tabs with it yet, I wonder if I have not enabled some feature or that it’s
incompatible with Firefox 1.0 in that respect. Or that my brain is fried, who knows.

That’s one of the things that always irritates me in Safari — my brain always expects the (new) last tab to be selected after I close the (old) last tab.
I also noticed that the FLST extension gets in the way of using the ‘close’ icon if you enable to have that on each tab (as I did). Trying to use it on the active tab makes it select the previously selected tab. When it’s no longer active you can successfully use it. That started to get on my nerves after only a short while so it’s bye-bye for that extension, alas.