Windows NT was originally OS/2 (and retained OS/2 code compatibility for some time because it had to run a version of IBM's Lan Manager for the server). IBM told Microsoft if they called it OS/2 they'd sue, so Microsoft named it NT and brought in Cutler to finish it. Cutler had much of it rewritten to be more like VMS.
Multiplan was not out before VisiCalc because VisiCalc was the first electronic spreadsheet ever - in the world ever - and ran on the early Apple II. Dan Briklin presented it as a college project and was told by his prof the concept was entirely absurd. He went ahead and wrote it anyway. SuperCalc, running on CP/M-80 was the first successful imitation of VisiCalc and all others came later.
If you've been reading books that say otherwise, you're reading too many books published in Redmond.