securelevel [1] is a similar feature from/for FreeBSD. As an example, it could be used to build e.g. a true append-only syslog server which even root would not be able to manipulate the data without a reboot or, in combination with other techniques like a capiscum-sandboxed tcpdump implementation, highly secure network appliance.. plenty of use-cases.

[1] https://www.freebsd.org/cgi/man.cgi?query=securelevel&apropo...