Source : Free On-Line Dictionary of Computing

PL360
     
        {Structured assembly language} for the {IBM 360} and {IBM
        370}, with a few high-level constructs.  Syntactically it
        resembles {ALGOL 60}.  Its grammar is defined entirely by
        operator precedence.
     
        ["PL/360, A Programming Language for the 360 Computers",
        N. Wirth, J ACM 15(1):37-74 (Jan 1968)].
     
        (1995-01-05)