It’s wild that OpenBSD still supports the architectures it does. I literally learned how to program on a G4 Mac running OpenBSD back in 2000. I think it was version 3.0 but I don’t really remember. It was a wonderful experience, and I chose OpenBSD because it was the only UNIX-like OS I could get to boot on that machine (I struggled to understand Debian’s esoteric instructions for weeks before I gave up). OpenBSD, by contrast, had essentially the same install program it has to this day. At the time, there were no printed books for OpenBSD, but I read the (surprisingly good) man pages and supplemented with a used copy of the FreeBSD handbook I bought on eBay. Good times.