Open Source PL/I (Programming Language One) Compilers

XPL is a dialect of PL/1 documented in the book "A Compiler Generator" by McKeeman, Horning and Wortman, published by Prentice-Hall, 1970, ISBN 13-155077-2. In 1996 David E. Bodenstab ported the compiler to the Intel 486 running on FreeBSD Unix. In 2020 Daniel E. Weaver ported the compiler to Linux. As of November 2020 the Linux port runs on both Linux and the Apple MAC. However Apple has deprecated the 32 bit mode of the Intel processors. This XPL compiler is not compatible with 64 bit execution. Building this compiler requires the XPL to C translator written by Daniel Weaver which can be found here: https://sourceforge.net/projects/xpl-compiler/

This is a self compiling XPL compiler for the Modcomp III/IV and Classic. The XPL language is described in the book "A Compiler Generator" by McKeeman, Horning and Wortman. This project has two compilers. The first was written in the late 1970's and released to the Modcomp Users Group (MUSE). The second compiler is an extension of the first that includes a Common Sub-Expression optimizer. XPL was used to write the HAL/S compiler for NASA about the same time this XPL compiler was being developed but this is not the compiler used to create HAL/S. I am in need of technical documentation for the Modcomp Classic and the MAX IV operating system. Please let me know in the discussion section is you have documentation from Modular Computer Systems.