Earlier quoted context omitted.
Trond Werner Hansen is not a non-profit. In fact, he's not even a corporation. As a side note, 80% of features in Mozilla were first done in Opera. I even remember a Firebird (as it was called back in the day, before version 1.0) fan or zealot badmouthing Opera and its tabs as being a ridiculous and unnecessary feature. After just four months, that feature was copied. It seems that crowd has not changed even a little…
I don't think the event you describe was possible, because Mozilla had tabs before Phoenix/Firebird/Firefox even existed. In any case, Opera copied the tabs from other browsers too, so I'm not sure what's your point with that story. By the way, it wasn't just about the OSS license. Back in the day Opera had a big honking ad right in the main window. They only released an ad-free version in 2005, when Firefox already…
That big ad is a sad bit of Internet history. A wasted opportunity.
Also: they had a deal with Google to make it the default search engine before Firefox had one.