This is a companion piece to my list of computers that I have owned or used.
CP/M
This OS ran on the early hobby computers circa the mid 1970s. It was an 8 bit OS.
PC-DOS, MS-DOS all versions
When IBM introduced the PC they offered several different choices for the Operating System. One choice was CP/M-86 which was a newer 16 bit version of CP/M. Another choice was PC-DOS from Microsoft. Microsoft didn't write this. They bought it from a company called Seattle Computer Products, I believe. I think there was a version of UNIX that was available, but I really don't remember.
When Apple introduced the Apple III, it came with an operating system that displayed a horizontal menu at the top of the screen. This was identical to, or nearly identical to the UCSD OS that could be run on the IBM Machines. UCSD also wrote a Pascal Compiler (interpreter?). I think the OS was written in Pascal. For the time, this was very forward thinking. I learned Pascal in College. It was considered more formally 'correct' as a language than C, which was being used by Bell Labs, and the phone company. This OS seemed to die out though due in part to the fact that the Apple III didn't sell well, and I believe more software applications were available for PC-DOS on the PC (Visi-calc)
Windows 1
This OS never sold I don't think. It was black and white only and applications were shown in non-overlapping window panes on the screen. I remember seeing the Clock. If there was a Windows II I never knew about it.
Windows 3, 3.1, 95, 2000, XP
Perhaps with all industries, but in mine at least there are periods of great excitement and dull periods where things plod along. The advent of the PC and the Apple and other early personal computers was very exciting. After a while, most people realized that these machines weren't really necessary or good at saving your recipes! However, business caught on with Visi-calc and word processing. Still, these early personal computers were quite 'geeky'. When Apple learned about Xerox-PARC and then came out with the Lisa, followed by the Macintosh, the GUI (Graphical User Interface) was born. Enter the Mouse. A new age of excitement! Now, the marketers proclaimed, everyone needs a PC! Microsoft got on board with Windows 3.0 (a bit of an 'oops' product that was soon replaced with v3.1). Yippee!, the personal computer world is now all about point and click!
Things got dull again, until we all hooked up to the internet!
Linux (Knoppix)
Xenix
USCD