Comparison of PL/I preprocessors, and discussion of preprocessor implementations.

The PL/I language is defined by the standard ISO/IEC 6522:1992 and ANSI INCITS 53-1976 (R1998).

The PL/I preprocessor is not part of the language standard and different compilers support slightly different versions of the preprocessor language.  This wiki will provide an opportunity to compare and contrast the different preprocessors, with a view towards defining a preprocessor standard.

This discussion is implemented as a Wiki rather than a set of static pages to allow participants to make comments, corrections, etc.