GNU Hurd (usually referred to as the Hurd) is a collection of servers that run on the Mach microkernel designed as a replacement for Unix kernel, released as free software under the GNU General Public License.
GNU Hurd (usually referred to as the Hurd) is the kernel of the GNU computer operating system. It has been under development since 1990 by the GNU Project of the Free Software Foundation, designed as a replacement for Unix kernel, and released as free software under the GNU General Public License.