A name for a system with a Linux as the Kernel and GNU as the UserSpace utilities and applications.

The hybrid nature is a product of the fact that GNU's TheHurd isn't yet production grade and Linux doesn't come with (m)any UserSpace utilities and applications.

However, neither the XServer and corresponding applications nowadays expected on a workstation nor Apache, SendMail/Qmail/Postfix/Exim, Samba, and other daemons required to run a server are written by the GNU project. Since the GNU utilities only make up a fraction of the UserSpace code required for any modern system the legitimacy of the "GNU/Linux" term has been questioned as arbitrary: one might ask why a system running the Apache WebServer isn't called ASF/GNU/Linux.