OpenBSD is a free, open-source Unix flavor maintained by The OpenBSD Project. The OpenBSD project focuses on providing security and integrated cryptography. OpenBSD runs on several platforms including Intel-based PC systems, Sun Sparc machines, HP300/HP400 and Apple Macintosh computers.
The OpenBSD project produces a FREE, multi-platform 4.4BSD-based UNIX-like operating system. OpenBSD emphasizes portability, standardization, correctness, proactive security and integrated cryptography. OpenBSD is freely available and developed by volunteers. The project funds development and releases by selling CDs and T-shirts, as well as donations from organizations and individuals.