[JdeBP]

That's not specifically OpenBSD, though. The BSD world is not the monolith that it was back in the 1980s.

[avadodin]

True. No relevance to macOS and iOS.

With due mention to FreeBSD's jails, BSD's security image developed mostly from OpenBSD which is said to have gained its security focus due to NetBSD being so insecure that the NetBSD folks were able to hack into DeRaadt's forked OpenBSD.

Android's Bionic was based on or heavily influenced by OpenBSD's libc iirc, though.