And besides the GUI, all unixes were way more cutting edge than anything windows except NT. Only when that went mainstream with XP it became serious.
I know your 20 year timeframe is after XP's release, but I just wanted to point out there was a time when the unixes were way ahead. You could even get common software like WP, Lotus 123 and even internet explorer and the consumer outlook (i forget the name) for them in the late 90s.
Could you please elaborate?
IBM made it super suit and tie. Geriatric colour schemes with dark colours, formal serif fonts and anything cool removed.
Functionally it was the same (even two or three features were added) but it went from "designed for people" to "designed for business". Like everything that IBM got their hands on in those days (these days they make nothing of consequence anymore anyway, they're just a consulting firm).
It was really disappointing to me when we got the "upgrade". And HP was really dismissive of VUE because they wanted to protect their collaboration deal.
I think 10.30 was peak HP-UX. 11 and 11i were the decline.
Being stuck in Ubuntu 14.04 you can actually take a look out the window and see what you are missing by being stuck in the past. It hurts.