OpenBSD

Rank: #7

Website: https://www.openbsd.org/

IRC:

#openbsd on Freenode with 775 users online

Description

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.

OpenBSD is developed entirely by volunteers. The project’s development environment and developer events are funded through contributions collected by The OpenBSD Foundation. Contributions ensure that OpenBSD will remain a vibrant and free operating system.