Source : Free On-Line Dictionary of Computing

Sequential Parlog Machine
     
        (SPM) The {virtual machine} (and its machine code) for the
        {Parlog} {logic programming} language.
     
        {(ftp://nuri.inria.fr/lang/Parlog.tar.Z)}.
     
        ["Parallel Logic Programming in PARLOG", Steve Gregory,
        Addison-Wesely, UK, 1987].