Source : Free On-Line Dictionary of Computing

SPL/I
     
        Signal Processing Language One.
     
        (Or "SPL/1") A language designed by {Intermetrics} for
        acoustic {signal processing}.  It has graphics and
        multiprocessing features.
     
        ["SPL/I Language Reference Manual", M.S. Kosinski,
        Intermetrics Report 172-1 (July 1976)].
     
        (1995-01-19)