'''PL/I''': '''Programming Language One'''

Descendants of PL/I (PliLanguage), arguably including SQL.

PL/I derivatives include:

* PL.8 (PlDotEight): PL/I subset for the IBM 801 research RISC microprocessor.
* PL/AS: reportedly the successor to PL/S (PlsLanguage).
* PL/C: a PL/I subset designed at Cornell University specifically for students (S. Worona &al.: ''User's Guide to PL/C'', Cornell U., June 1974; H.L. Morgan &al.: "PL/C: A High Performance Compiler". ''Proceedings of the SJCC'', AFIPS 38:503-510 (1971)).
* PL/M (Programming Language/Microcomputers): a PL/I subset for Intel microprocessors.
* PL/S (PlsLanguage): the IBM programming Language [for] Systems, but only for IBM internal use, which was customarily used with its interleaved generated S/370 assembly code.
* PL/SQL (PlSql). ''AnswerMe: Is it really PL/I derived, or is just the name so (making it PL/I deprived)?''
* PLUM: teaching & research subset of PL/I for the Univac 1100 at U. of Maryland (M[arvin] V. Zelkowitz: ''PL/I Programming with PLUM'', Paladin House, 1978).
* PL/X: reportedly the successor to PL/S (PlsLanguage) and PL/AS, still officially only for IBM internal use, but with the distinction of being ObjectOriented.
* PL/Z: a PL/I subset for Zilog microprocessors, most intriguingly for the Z8000.
* Rexx (RexxLanguage)

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I first heard of Rexx in 1988, but I never heard that it was derived from PL/I, and I really think I would remember if I had heard that. Can this be confirmed? ''Sorry, I don't see much relationship between PL/I and Rexx - Rexx was designed as a much more powerful replacement for a scripting language in common use on IBM mainframes called EXEC2 language.  It was later extended to other platforms.  It does share the convention for comment statements with PL/I, but that's about all!''
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CategoryProgrammingLanguage