i can’t imagine life without pf
Having used OpenBSD for over 10 years I rank it as the #1 for my data processing needs. I love the security, the obsessive approach to correctness, the license, and of all its built it components, pf. pf is simply short for packet filter. More specifically it is the kernel level packet filter that ships with OpenBSD. We have ipf and a certain un-named individuals off-by-one phrase of the BSD license, license to thank. When in 2001 the un-named individual made a fuss about his license not allowing for changes to be re-distributed the fine fellows at OpenBSD had no choice but to pull ipf out of the default source tree. The few versions of 2.9-current|beta that shipped without a firewall were well worth the result.
Although on a much smaller scale, these circumstances are similar to those which caused what we know as BSD to exist in the first place. You are free to Google the AT&T vs. UC Berkley CSRG wars for a historical perspective. A certain computer scientist of Finnish descent also decided to roll his own System V clone due to these court precedings, but good luck convincing your neighboorhood Linux enthusiest of this fact.
What these situations share is when faced with legal copyright problems the BSD spirit has always been to re-write the code from scratch with a suitable license. Suitable in the BSD sense. Copyright wars are beyond the scope of my limited time on Earth.
Now that I am totally off track I will just say yes, they rolled their own firewall and packet filter now known as pf. Coupled with the tools and utilities pf has been a life saver over the years. Spamd and synproxy alone have cleared me from certain death on numerous occasions. I just felt so inclined to write a bit of thanks and bring some light to the OpenBSD project. I wont even get started on OpenSSH, nearly everyone on the face of the computing planet uses in some form this program, Theo and crew should be better compensated.
But there is a flip-side. Although OpenBSD, OpenSSH, OpenBGPD, etc are all 'free' and available via the BSD license I myself have I donated hardware and bought a rather large stock of items. I am especially fond of the wireframe Beastie shirt and there posters.