OpenBSD packages: an overview

Peter N. M. Hansteen has a long writeup about using and creating ports on OpenBSD, which is apparently a reprint of an article he wrote for BSD Magazine back in 2008.  I don’t remember if I read it, so it’s new to me, in any case.  Port and package creation across the BSDs is juuuust close enough that reading about one version will leave you with a good guess about the others.