The history of PL/I stretches back to the 1970s when IBM, at the prompting of the SHARE user group, delivered the first PL/I compiler so that users would have a language with the combined strengths of Fortran and COBOL. IBM then delivered three releases of OS PL/I Version 2 in the 1980s and PL/I for MVS and VM in the early 1990s. All of these releases were based on a common code base that gradually became old, plus both hard and expensive to enhance and maintain.
However, with the advent of the PC, IBM built a completely new PL/I compiler that was shipped first on IBM® Operating System/2® (OS/2) and then ported to Microsoft Windows, the IBM® AIX® operating system, and the mainframe. With this compiler and the 12 consecutive years with a new release of the IBM® z/OS® version, IBM has improved optimization of PL/I programs, enhanced their exploitation of IBM® System z® architecture, addressed many customer requirements, and introduced numerous application modernization features.
IBM continues to have a strong commitment to the PL/I language, particularly given its widespread use in many business-critical applications. The current family of IBM PL/I implementations consists of the Enterprise PL/I compiler for the mainframe and the PL/I for AIX compiler, both of which share a common, nearly identical front-end code base, which ensures portability between those platforms.
We are opening this forum to create more direct communication between users of our PL/I compilers and the IBM compiler development organization. We hope you'll find the content informative and interesting, and we look forward to your contributions through questions, comments, and ideas.