Source : Free On-Line Dictionary of Computing

Hurd
     
        The Hurd will be the foundation of the whole {GNU} system.  It
        is built on top of the {Mach} 3.0 {kernel}, a free
        {message-passing} kernel developed by {CMU}.  Mach's {virtual
        memory} management and message-passing facilities are
        extensively used by the Hurd.  The GNU C Library will provide
        the {Unix} {system call} interface, and will call the Hurd for
        needed services it can't provide itself.
     
        One goal of the Hurd is to establish a framework for shared
        development and maintenance.  The Hurd is like GNU {Emacs} in
        that it will allow a broad range of users to create and share
        useful projects without knowing much about the internal
        workings of the system -- projects that might never have been
        attempted without freely available source, a well-designed
        interface, and a multi-server-based design.
     
        Currently there are free ports of the {Mach} {kernel} to the
        {Intel 80386} {IBM PC}, the {DEC} {PMAX} {workstation}, the
        {Luna} {88k} and several other machines, with more in
        progress, including the {Amiga} and {DEC} {Alpha}-3000
        machines.  Contact , if you want to help with
        one of these or start your own.  Porting the GNU Hurd and GNU
        C Library is easy (easier than porting GNU Emacs, certainly
        easier than porting GCC) once a {Mach} port to a particular
        {platform} exists.
     
        [June 1994 GNU's Bulletin].
     
        (1994-12-07)