Like others have said. It’s been 18 years since Mac started the move from 9 to X (a play on 10, uniX, and neXtstep). 17 years ago X was on all boxes with some dual/system boot options and a couple years after, 9 was gone. I was a dyed in wool Mac fan from the 80s (when all the good typesetting and music software was there) but by 1999 I was within a year of giving up on Mac for some kind of *nix when they made the leap, put out the beta, and I was allowed to remain in their camp.