On: Vivaldi 2.0 – includes sync, resizable tab tiling,...

[knfzn]

Firefox has been out for 25 years? Or are you referring to Mozilla also?

[_Codemonkeyism → knfzn]

Mosaic on an SGI or VAX/Tektronix not sure which one arrived first, we had both in our Unix pool at university.

[djsumdog → _Codemonkeyism]

NSCA Mosaic also made its way into IE. It's gone now, but as late as IE6, it was still referenced in the About dialogue.

[Blaiz0r → knfzn]

Must be Mozilla.

Phoenix was a breakout browser from the Mozilla suite, before it was renamed to Firefox, and that was around 2003 I think.