I can top that: not only I used it as my main browser while it was still called "Firebird", but I also used as my main browser its predecessor Mozilla back when

I can top that: not only I used it as my main browser while it was still called "Firebird", but I also used as my main browser its predecessor Mozilla back when its version numbers were single-digit "milestones". For those who didn't experience these early versions: they crashed a lot, and opening more than one window (there were no tabs back then) increased the chances of a crash so much that after 2-3 windows having it crash was almost certain. (Before that, I had used Netscape, starting with Netscape 2.)