Pretty much all of this went over my head. brb 🤔
Discussion
https://en.wikipedia.org/wiki/NetBSD
Chances are, it's running on something in your house. Most often a router or appliance.
The Unix Philosophy is also a very interesting thing to read about. It favored small, composable programs that did one thing, and did it well vs. mega apps.
https://en.wikipedia.org/wiki/Unix_philosophy
Definitely a rabbit hole to go down.