> Perhaps ironically, this was also the genesis of Firefox

That's not entirely accurate (or at least, while accurate, is missing a lot of significant context) Mozilla was creating within Netscape, not in opposition to it, as a steward org for the open-sourcing of Navigator & Communicator. Even when Netscape was acquired by AOL, AOL continued to fund[0] Mozilla for years after the acquisition.

[0] https://web.archive.org/web/20050324025052/http://www.wired....

But after that, IIRC Mozilla Suite was big, clunky and stagnating. And Phoenix, I mean, Firebird, I mean, Firefox was a lean spin-off.

It was a spin-off within Mozilla though - not a rival fork.

Firefox, however, was not. It was created because people didn't use most of the tools built into the Mozilla suite, and they were difficult to port (because they had a Motif frontend AND a GTK frontend).

https://website-archive.mozilla.org/www.mozilla.org/firefox_...

That is the case, but even then Firefox really was a fork, within Mozilla.

Mozilla was created in 1998 to open-source Netscape Communicator suite. Mozilla released its own suite, also called "Mozilla" (e.g. "Mozilla 1.0" [0])

Independently of that effort, Dave Hyatt and Blake Ross made an experimenal, cut-down version of just the browser part of the suite, which they called "Phoenix", as in a Phoenix rising from the ashes. That's a fork. That's a fork by any metric.

They later rebranded Phoenix as Firefox, and eventually the Mozilla suite was abandoned. Mozilla changed tack in 2003 and switched to developing Firefox and Thunderbird as independent products [1]

[0] https://www-archive.mozilla.org/releases/mozilla1.0

[1] https://www-archive.mozilla.org/roadmap/roadmap-02-apr-2003