In 1978, Tim Patterson at Seattle Computer Products made a quick clone of it for beta testing a new 8086 based computer, and nicknamed it "QDOS" for "Quick and Dirty Operating System". By about 1980 or so, IBM Was designing and coming up with their own Personal Computer - what would come to be the IBM Personal Computer 5150 - and Bill Gates and Kildall were working together on getting CP/M on it. Accounts vary but basically, it seems that someone at the meeting told IBM That Gary Kildall was out flying his leisure aircraft while they were bluffing IBM that Microsoft had an O/S all ready to go. THen Microsoft paid $15000 to Tim and modified his QDOS into what would be released as IBM Personal Computer DOS - or PC-DOS - with the PC in 1981, under-cutting Digital Research by selling it for a mere $99.99. Microsoft also left some detail in their contract to allow them to license it out to competitors as MicroSoft Disk Operating System - or MS-DOS - explaining where the term "MS-DOS" actually comes from". Digital Research would continue with their own DR-DOS branded version, basically the true outgrowth of their CP/M program from the 70's, and then in 1994, as Microsoft was starting to sweep DOS under the rug starting with WIndows 95, Jim Hall came up with a OpenSource DOS Alternative known as FreeDOS.

Now what IS DOS? DOS Is a Command-Line driven Operating system where the entire operating system is handled by typing "mnemonics" - yes, the namesake of the now popular term "memes" - at the command prompt. No, you're not yelling at the O/S as doomer guy, but you are typing abbreviated commands ie DIR/w or CD\Monkey.VGA\Monkey.EXE or del c:\windows\system32\drivers\Crowdstrike\c-00000291*.sys for a more recent use of this vintage technology that shows it's still somewhat relevant even in 2024 when DOS is basically *dead* and most people run either Windows NT, MacOS, or Linux on their systems.