Computer Cousins: The Atari ST and DOS PCs
I heard it's DOScember...
In 1984 when the Atari ST hardware was being finalized, there was a need to get an operating system on it. Atari realized that with their short timeframe they could not possibly create an OS for it on their own1, so they looked around for other vendors to see what was available for an OS with a graphic user interface (GUI).