The GNU Hurd

[ Thanks to Nobody for this link.

“Most Linux users out there, think that their whole
system is named just “Linux” (or perhaps the distribution name).
For a large number of reasons, which I do not intend to analyse on
this post, this is not, and should not be the case. The actual name
is GNU/Linux since only the Linux Kernel is “Linux” and the rest of
the system (including some vital parts such as glibc or GCC) are
parts of the GNU Operating System.”