You're right. Phoneix/Firebird were basically a clone of the obviously-best-to-copy Opera features but without the ad bar, with a more native-feeling UI, and maybe (IIRC?) even lighter and faster to launch. Built-in popup blocking, very lightweight and snappy, tabs, free, no ad bar. Those were the selling points, and aside from the last two and slightly odd-feeling UI widgets, Opera had them already.

We lost "lightweight and snappy" way back in FF 2.0, and every browser blocks pop-ups now. Today's equivalent would be making ad blocking built-in and on by default, which it isn't. The advertising and constant "we updated!" tabs opening up (yeah, great, I don't give a shit, stop telling me) are at least as annoying as Opera's adbar was, IMO. Hopefully we get a spin-off browser eventually that gets back to FF's roots, and then eventually eats it, like FF did Mozilla Browser.

>"we updated!"

Well "we updated" mobile firefox to 79, and broke almost all add-ons, forgot the bookmarks, most visited sites, effective homepage and made it crash every hour or so. I can't recall more broken version of Firefox since the times it used to be Mozilla Suite.

Modern FF makes Mozilla Suite look svelte and respectful. It's heavy and loud. I use it when I'm not on macOS or iOS and need a full-fat (and then some) browser, but I'd have a hard time recommending it to anyone.

> The advertising and constant "we updated!" tabs opening up (yeah, great, I don't give a shit, stop telling me) are at least as annoying as Opera's adbar was, IMO.

This was actually the last straw for me. I had 30 tabs open, and Firefox decided to take an update. Any time I opened a new tab, it demanded I restart my browser, closing everything, and refused to function. That level of interruption was so unacceptable I switched (back) to Chrome.

> I seem to remember that Opera was the first stand-alone browser that brought the world tabbed browsing.

Nope. There were other browser before that. And Opera did not have Tabs back then. They had MDI with a button-bar for document-access. Mozilla was the first one delivering a real tabbed interface, and was later copied by opera and others.

At the end there was a bunch of features coming from several browsers (but mostly mozilla and opera), which improved each other in tight competition; so it's a bit complicated to say what originated from whom.

> One big thing Opera didn't invent was the use of the address bar for more than URLs, so you could search and autocomplete on it. I think some combination of Chrome+Firefox iterated on that concept.

Pretty sure it was one of the notable innovations in the original Chrome beta release.

>Chrome+Firefox iterated on that concept.

Chrome, of course. It integrated google straight in the URL. To this day, I still don't use URL as a search bar, and press ctrl+K (instead of ctrl+L)...