View --> Digit Grouping.
That's kinda cool. It never occurred to me to look for an RPN PC-utility calculator. It's funny - I use an HP calculator* for my "math" needs when I'm not sitting in front of the computer (98.8% of which are mere arithmetic, for that matter, with the other 1.2% being pathetically simple algebra😉) and I barely even think about the fact that I (naturally) use RPN on it... But I think I would find it odd to switch over to it with a PC utility, just due to decades-long habit.rpn? If you don't do rpn, you don't do real math :^P