OpenBSD is a Unix-like computer operating system descended from Berkeley Software Distribution (BSD), a Research Unix derivative developed at the University of California, Berkeley. In late 1995, Theo de Raadt forked it from NetBSD. Besides the operating system as a whole, the project maintains portable versions of many subsystems, most notably OpenSSH, which are available as packages in other operating systems.
The project is known for its developers' insistence on open-source code, good documentation, code correctness, and security. It has strict policies on licensing, preferring the ISC license and other variants of the Simplified BSD License. Many of its security features are optional or absent in other operating systems. Its developers frequently audit the source tree for software bugs and security holes.
De Raadt coordinates the project from his home in Calgary, Alberta, Canada. Its logo and mascot is a pufferfish named Puffy.