PL/I had features from COBOL, FORTRAN and ALGOL. One advantage over FORTRAN IV was that PL/I had complex number types and the associated math libraries. This m

PL/I had features from COBOL, FORTRAN and ALGOL. One advantage over FORTRAN IV was that PL/I had complex number types and the associated math libraries. This made certain engineering calculations much easier, for example, transmission line calculations. It suffered from being IBM proprietary and from its size and complexity, which were too great for the early wave of minicomputers. Hence the rise of the much smaller and more open C language.