> These features made possible Windows 3.0, OS/2, and early Linux.
And also--before Linux--SCO Xenix and then SCO Unix. It was finally possible to run a real Unix on a desktop or home PC. A real game changer. I paid big $$$ (for me at the time) to get SCO Xenix for my 386 so I could have my own Unix system.
Don't forget Venix. It was the first true Unix that could run on a stock IBM PC, and beat Xenix on that platform by months.
Xenix 2.1 could run on the IBM PC XT with Intel 8088 in late 1983, IIRC, and even before that on the Altos 586 which had MMU as an external chip.