http://www.openbsd.org/

Only two remote holes in the default install, in a heck of a long time!

The OpenBSD project produces a FREE, multi-platform 4.4BSD-based UNIX-like operating system. Our efforts emphasize portability, standardization, correctness, proactive security and . OpenBSD supports binary emulation of most programs from SVR4 (Solaris), FreeBSD, Linux, BSD/OS, SunOS and HP-UX.

OpenBSD is freely available from our FTP sites, and also available in an inexpensive 3-CD set.

Pre-orders for the upcoming  release are enabled at our .

The current release is  which was released Oct 18, 2009.

OpenBSD is developed entirely by volunteers. The project pays for the development environment and developer events by selling  and by accepting  from organizations and individuals. These finances ensure that OpenBSD will continue to exist, and will remain  for everyone to use and reuse as they see fit.  and  are available as well, but do not fund the project.