DR DOS was Digital Research's MS-DOS clone. For a while it had more features and ran better than MS-DOS. In the mid-90s, Caldera bought the rights to DR DOS so they could bundle it with their OpenLinux Linux distribution. They briefly released its source code (renamed to "OpenDOS"), but not as an open source license. The license only allowed free use for educational and evaluation purposes. You were required to buy a license from Caldera after 90 days for commercial entities or after a "reasonable period" for non-commercial entities. They then closed the source code again after a few months. The Enhanced DR-DOS project is based off this code release. They seem to have replaced the license in the repo with an email log that releases the code to CP/M as open source, but doesn't mention DR DOS at all. This is a bit sketchy but DR DOS has no commercial value so I doubt anyone will mind.

The biggest impact Caldera's purchase of DR DOS had was that they were able to sue Microsoft for not making Windows 95 compatible with other DOS's besides Microsoft's. Caldera were able to demonstrate Windows 95 booting on DR-DOS with the assistance of a small TSR, which helped the lawsuit (see https://msfn.org/board/topic/109018-windows-98-in-dr-dos/ ). This functionality was never released publicly. Microsoft ended up settling out of court and paying Caldera $280 million.

The idea is to make it more compatible with DOS 6.x

So I believe things like Long filenames are not emphasised.

I refuse to create a facebook account. There are alternatives[0].

0. http://www.svardos.org/?p=forum

That's interesting, Firefox and Safari on iOS 18 do open it - didn't know that they changed the default behaviour in 26 apparently.

But yes it's HTTP-only, I think it's by choice.