OpenBSD is a free and open source operating system with a strong focus on security and clean audited code base. OpenBSD was forked in 1995 from NetBSD. OpenBSD follows a "secure by default" philosophy and sane default settings. The OpenBSD project is directly responsible for many other popular child projects such as:
- OpenSSH - OpenBSD Secure Shell is a suite of security-related network-level utilities based on the Secure Shell (SSH) protocol. It works on Linux, NetBSD, FreeBSD, and other Unix-like systems.
- OpenNTPD - A Unix system program implementing the Network Time Protocol to synchronize the local clock of a computer system with remote NTP servers. It also act as an NTP server for NTP clients.
- OpenBGPD - Turn your Unix computers to be used as routers.
- OpenSMTPD - Turn your Unix computers to be used as an email server.
- PF - Firewall.
- CARP - Its primary purpose is to provide failover redundancy, especially when used with firewalls and routers. I
- LibreSSL - Fork of OpenSSL.
- OpenBSD httpd (a web server that is based on relayd. It is secure, serves static files and supports FastCGI and TLS) and relayd (a FREE load-balancer, application layer gateway, transparent proxy, and SSL/TLS gateway).