I'm seeing FreeDOS mentioned here, but I do wonder what practical use it is being put to. I only ever see it as something computer makers write into the hard disk because they have to put something there, which gets promptly wiped and replaced with a variety of Linux. (Why they couldn't ship an empty HD, I have no idea.)
It was a workaround from the time the Microsoft OEM agreement required them to ship an operating system, but the contract didn't specify which system.
Anyway, FreeDOS is useful for updating BIOS images, it also seems to run a lot of legacy industrial equipment, you can play retro games with it, and Jim Hall has a wonderful YouTube channel where he regularly shows using FreeDOS as an educational tool: https://youtube.com/@freedosproject
