> It seems that every version of MS-DOS from v2.0 onward was actually developed by Compaq. I had no idea.

The article is wrong about when this occurred—Compaq DOS wouldn't have been in stores in 1982; 1983 is likely the correct year—but regardless, this is an astounding revelation.

These other versions of MS-DOS were licensed by PC clone OEMs and bundled with the PC clones. Microsoft didn't sell MS-DOS directly to consumers until later.

According to https://en.wikipedia.org/wiki/Ms-dos, MS-DOS 3.20 was the first consumer retail version of MS-DOS (then MS-DOS 5.0 was next).