I used PL/I in about '68 to do transmission line calculations. It was great for the task because it had a complex float type and a full set of complex math func

I used PL/I in about '68 to do transmission line calculations. It was great for the task because it had a complex float type and a full set of complex math functions. It was a lot better than Fortran or Cobol at the time. I think it did not succeed because the PL/I compiler was too big and slow for the first generations of minicomputers in the '70s. There may have been intellectual property issues that kept it from being more widely used as well.