Really? They might use some GNU programs, but I’m sure the default user land for OpenBSD is all theirs. Just because you know cp etc. as GNU utils doesn’t mean the BSDs use the same ones. They are just part of the operating system. https://github.com/dcantrell/bsdutils tried to collect various BSD implementations for example
The “coreutils” that macos uses by default are all older shitter bsd versions. I discovered this when half of my scripts and commands didnt work properly.
Silly me thought I could just bring my cash scripts over and not have any major issues (I’m not doing anything crazy). But even something as simple as grep didn’t work right because it could recursively search directories in the old bad version Mac comes with.
All of the gnu versions are much better and you can install them with homebrew.
People used to care a lot. The GNU utils absorbed everything all the old Unix vendors did. This made them comparatively heafty back when a high end workstations might have had 64MB of RAM.
Now that Chrome takes up gigabytes per tab, nobody cares except a few old Unix curmudgeons.
