Source : Free On-Line Dictionary of Computing

XSB
     
        XSB extends the standard functionality of Prolog (being a
        descendant of PSB- and SB-Prolog) to include implementations
        of OLDT (tabling) and HiLog terms.  OLDT resolution is
        extremely useful for recursive query computation, allowing
        programs to terminate correctly in many cases where Prolog
        does not.  HiLog supports a type of higher-order programming
        in which predicate symbols can be variable or structured. This
        allows unification to be performed on the predicate symbols
        themselves in addition to the arguments of the predicates.  Of
        course, Tabling and HiLog can be used together.
     
        Version 1.2
     
        ports: Sun, Solaris, NeXT, Linux, 386 BSD, IRIX, HP-UX
     
        portability:	Generally to 32-bit machines.
     
        interpreter, preprocessor(HiLog), documentation
     
        XSB research group / SUNY at Stony Brook
     
        {(ftp://sbcs.sunysb.edu/pub/XSB/XSB.tar.Z)}.
     
        (130.245.1.15) E-mail: .
     
        (1993/07/28)