Also if firewalling/packet filtering was a consideration, ipfw was (is?) leaps and bounds nicer to work with than ipchains/iptables. This (c. FreeBSD 4.x) is what introduced me to FreeBSD.
OpenBSD’s pf (which got ported to FreeBSD) and it’s pf.conf still sets the benchmark for the most beautifully readable firewall rules.
The FreeBSD pf is an (very) old version of what is available on OpenBSD.
No it's not, it's a fork.
The config file syntax matches that of the old pre-4.5 OpenBSD pf but the code under the hood has seen much evolution. FreeBSD's pf is SMP-capable, for one thing, unlike OpenBSD's that "will only use one processor": http://www.openbsd.org/faq/pf/perf.html