In my experience

I began programming in 1971, in Fortran IV, using a Telex terminal with a punch-tape. Shortly after I graduated from college, I began working in IT, specifically with dedicated word processors. By the late '70's, I was working with desktop systems based on the Zilog Z80 and the Intel 8085.

I've had occasion over the years to work with early, proprietary OSes, CP/M, MS- and PC-DOS from v. 1.0 on, Windows 2 on, a variety of Apple OSes and several flavors of Linux. I honestly think that SimplyMEPIS 6.0 is the best conceived and quite possibly the best executed desktop environment I've used, to date. My heartfelt congratulations to Warren and the MEPIS team!