Debian GNU Hurd is a GNU operating system release built on Hurd. Hurd, which means "Hird of Unix-Replacing Daemons" (and Hird which means "Hurd of Interfaces Representing Depth"), includes many programs and libraries for the GNU OS. This free operating system aims at replacing the key functionalities of UNIX systems. This system tries to guarantee strong compatibilities with Unix systems while avoiding useless users restrictions. Even though Debian GNU Hurd is an experimental operating system, it is, in fact, the first port to an operating system that does not use Linux.