OpenBSD

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 integrated cryptography. 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.

The current release is OpenBSD 4.6 which was released Oct 18, 2009.

OpenBSD is developed entirely by volunteers. The project pays for the development environment and developer events by selling CDs through a collection of stores and by accepting donations from organizations and individuals. These finances ensure that OpenBSD will continue to exist, and will remain free for everyone to use and reuse as they see fit. T-shirts and posters are available as well, but do not fund the project.

Associated projects: OpenSSH, OpenBGPD, OpenNTPD, OpenCVS

Article Source http://www.openbsd.org/