NetBSD

http://www.netbsd.org/images/NetBSD-smaller.jpg

NetBSD is a free, secure, and highly portable UNIX-like Operating System available for many platforms, from 64-bit Alpha Servers and desktop systems to handheld and embedded devices. Its clean design and advanced features make it excellent in both production and research environments, and it is user-supported with complete source. Many applications are easily available.


 * http://www.netbsd.org/


 * http://www.netbsd.org/Documentation/

Also see: BSD, FreeBSD , OpenBSD