The keyword is "without outside dependencies " . Most of us have to integrate many systems and there outdated libraries are a big problem.

The last version of DOS also works really well for the things it was designed for. You still wouldn't start new projects targeting DOS if you could help it, even if it would satisfy your current requirements.

Well, we're talking a safe language. So, if want an archaic red herring, you'd be better bringing up Burroughs written in an Ada predecessor that was immune to most forms of code injection or crashes in 1961. If you want small and Ada, then Martes RTOS is one written in Ada that's still around. For small and secure, the Muen separation kernel can handle it.

Actually, I would, if my needs were simple enough. Rarely is it necessary to have much more in embedded fields. Have a look at MDOS, a modern reimplementation of DOS used in many modern embedded cases.

Edit: which is apparently now called adelian.