Who invented DOS?

Not especially great. See Seattle Computer Products and Tim Paterson .

86 DOS wasn’t really a brilliant invention. It was a DOS riff on CP/M.

Wow, @Zaku, flashback. My first computer was a Kaypro that ran on CP/M. Thanks for the memory! :-)

Microsoft got the idea for the Windows operating system from Apple, who in turn used the ideas from the brilliant research group at Xerox, who also came up with the mouse. Xerox was never able to cash in on the ideas and eventually stopped marketing computers.