Paper describing syntax and semantics of SIMPL-X, a transportable systems programming language based on PL/I with Algol features.

IBM research report describing the extension of PL8 to support 64-bit addressing, its implementation as a GCC front end, and the validation of the new compiler. Evaluation of PL8 as a language for highly reliable low-level programming.

Resources and links for PL/I. Compilers and tools list, bibliography.

Skeleton parser for PL/M implemented in Flex and Bison. The grammar describes PL/M 386 and where possible, will accept various other dialects.

Encyclopedia article containing a brief history of the language, a discussion of design and implementation issues, and the advances PL/I contributed to language design.

One of the original "compiler compilers", XPL is a derivative of PL/I and was widely ported. Documentation, links, and resources.