DOS is old code, so the humor comes from the paradoxial juxtaposition of touting the use of old code while simultaneously saying, "friends don't let friends run old code."

This superposition of statements is set against the backdrop of the tech idiom, "friends don't let friends" followed by some activity. [1]

This tech idiom is based on a decades-old advertising slogan, "Friends Don't Let Friends Drive Drunk," by MADD, Mother's Against Drunk Drivers. [2]

[1] https://www.google.com/search?q=%22friends+don%27t+let+frien...

[2] https://www.youtube.com/watch?v=qVuu8G8ww6s

> DOS is old code

Not necessarily! http://freedos.org/

Well, considering the last DOS version is 6.22 (or, if you stretch, Windows ME)... by virtue of running DOS, you're running old software almost by definition :) Yes, I know FreeDOS exists.

There were a few versions of DOS from other vendors available after MS-DOS for example IBM PC-DOS and DR/Novell/Caldera (same OS with name changes as the owner changed) DOS.

FWIW, OS/2 is actively developed, maintained for a price. I gather it's mostly for industrial control and ATMs these days.

I used OS/2 Warp 4.0 for a bit, when researching for my book on Windows NT. It's certainly not "DOS", or not only, as it's a protected memory kernel with DOS userspace. But it might be a DOS, or a direct descendant that has managed to swim all the way to 2022.

https://en.m.wikipedia.org/wiki/EComStation

And of course https://www.freedos.org

That wikipedia page makes it sound like os/2 is very much dead

It comes from C++, an object oriented programming language where friends don't let friends access their privates. A nerd joke basically.