This makes me wonder if Carmack's feelings on NeXTSTEP had anything to do with the decision to release the first publicly available release of Quake 3 on OS X only at first.
At the time, I remember the ATI Rage128 chipset being the big deal and reason for why Q3's beta came out first on Mac... but gosh now I wonder if it was the feelings for NeXTSTEP.
Q3test came out in 1999 - on the classic Mac OS he despised, even a bit before its final OS 9 incarnation. This was to get the biggest bugs ironed out on the most restricted hardware scope available as they were going HW accelerated only during a bit of a wild west period when it comes to that.
We were all only reading about OSX in the press at the time - and when Q3 first made it to OSX proper, it was through a third-party (Omni Group).
JC did however switch to OSX as his primary development environment for some time when Apple was the first to ship the Geforce 3 in 2001, which was really the generation of hardware needed to do Doom 3 justice.
A year later, it was all about ATI's new flagship card which pushed things further for his needs - back to windows, and I can't rembember from his .plan files whether he moved back before getting access to that hardware.
See https://web.archive.org/web/20000229083216/http://macweek.zd... .
At the time, I remember the ATI Rage128 chipset being the big deal and reason for why Q3's beta came out first on Mac... but gosh now I wonder if it was the feelings for NeXTSTEP.