As a cautionary note, this article isn't really about anything people are using today. "Unix" doesn't today mean anything very similar to what it meant in 1981.

As a cautionary note, this article isn't really about anything people are using today. "Unix" doesn't today mean anything very similar to what it meant in 1981. The Commodore PET, Apple II and MS-DOS 1.10 of that time did not have great user interfaces either. And a lot has happened since then.