Huh. I honestly thought AIX was dead by now. I remember porting something to AIX 20 years ago, it wasn't fun. I guess IBM stuff doesn't die, it just gets more expensive.
At the end of the 90s they had spent like 15+ years diverging from each other. Some more gracefully than others.
But at any rate, your comment implied it should be dead because it's so old. Which is a silly statement, considering just how old UNIX™/Unix systems actually are.