PF (firewall)

PF
Original author(s)Daniel Hartmeier
Developer(s)The OpenBSD Project
Initial release1 December 2001; 22 years ago (2001-12-01)
Repository
Written inC
Operating systemOpenBSD
TypePacket filtering
LicenseBSD license
Websitewww.openbsd.org/faq/pf/index.html

PF (Packet Filter, also written pf) is a BSD licensed stateful packet filter, a central piece of software for firewalling. It is comparable to netfilter (iptables), ipfw, and ipfilter.

PF was developed for OpenBSD, but has been ported to many other operating systems.