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. As an example of the effect OpenBSD has, the popular OpenSSH software comes from OpenBSD.
OpenBSD is freely available from our download sites.
The current release is OpenBSD 7.6, released October 8, 2024. This is the 57th release.