One of the goals for the OpenBSD project is to try being the most secure operating system. The OpenBSD developers say the open software development model allows them to take a "more uncompromising view towards security than other vendors are able to". To this end the developers have been auditing OpenBSD components on a file-by-file basis since 1996, and continue the process to this day. . . .
I'm busy and want to sleep soundly and not with one eye on my internet-exposed hosts. Therefore I picked OpenBSD 3.5 as the operating system for the firewalling router handling my new home office connection.

OpenBSD is one of the three major free Berkeley Software Design Unix derivatives, the other ones being FreeBSD and NetBSD. Unlike Linux, which is a kernel with a userland bolted on, the various free BSDs are complete operating systems, each with their own area of strength.

One of the goals for the OpenBSD project is to try being the most secure operating system. The OpenBSD developers say the open software development model allows them to take a "more uncompromising view towards security than other vendors are able to". To this end the developers have been auditing OpenBSD components on a file-by-file basis since 1996, and continue the process to this day.

Not saying that this is a fail-safe process, but the results speak for themselves: apart from a single security hole in SSH, there have been no breaches in the default OpenBSD installation for eight years.