The XPL Programming Language

The XPL programming language is a derivative of PL/I designed for compiler writing. XPL was first announced at the 1968 FJCC in San Francisco, CA. (See McKeeman, Horning, Nelson and Wortman below.) XPL is the name of both the programming language and the compiler generator system (or TWS: translator writing system) based on the language. The definitive description of XPL is the book A Compiler Generator by William M. McKeeman, James J. Horning, and David B. Wortman (ISBN 13-155077-2) ("The Orange Peril") - see Table of Contents. A number of languages are based on XPL, including the PL/M family and Hal/S. [MORE] XPL is not any of the following: A scripting language for the Note Bene word processor. A MIDI programming language for Amiga. A language called eXtensible Programming Language. A Pascal-like language named XPL0.

XPL Ports:

• Original XPL Compiler for System/360 and System/370. [1970]
  (SHARE Program number 360D-03.2.015)
  A reconstruction of this tape is available [zip file, 156k]
• Optimizing Compiler for System/370. [source, 180K]
• Univac 1100 Series. [1975]
• ICL System 4.
• CDC 6000 and CYBER Series.
• XDS Sigma-5. [1971]
• XDS Sigma-7.
• Digital Equipment PDP-10 (DECUS program 10-291) and DECSystem-20 (DECUS program 20-122) from the PDP-10 Software Archives.
• GE/Honeywell 645 - Multics. [1971] [zip file, 47K]
• Intel FreeBSD. [1996]

XPL Resources:

• XPL Language Description (requires frames).

• XPL for IA-32 Linux Linux port of Dave Bodenstab's x486 version with "submonitor" in PL/Iine.

• XPL for System/390 This version is written in PL/I and generates S/390 machine code.

• XPL for PC-DOS (not a port, this version interprets the S/360 instruction set).[zip file, 128K]

• Stony Brook Pascal, a Pascal compiler for S/370 from the State University of New York at Stony Brook built with XPL. (requires Yahoo signin)

• BNF for XPL as HTML or plain text

• Snippet of XPL code (XCOM itself is the best example).

• Free Compilers page for XPL.

• Dictionary of Computing entry for XPL.

Bibliography:

• Alexander, W.G. and Wortman, D.B. "Static and Dynamic Charactersistics of XPL Programs." IEEE Computer Nov 1975; 41-46.
• Ancona, Massimo, Dodero, Gabriella, and Durante, Ercole Luigi "Cross software development for microprocessors using a translator writing system" Proceedings of the 4th International Conference on Software Engineering 1979: 399-402.
• Kamnitzer, S.H. "Bootstrapping XPL from IBM/360 to UNIVAC 1100." ACM SIGPLAN Notices May 1975: 14-20.
• Karger, Paul A. "An Implementation of XPL for Multics." SB thesis. Massachusetts Institute of Technology, 1972.
• Klumpp, Allan R. "Space Station Flight Software: Hal/S or Ada?" Computer March 1985: 20-28.
• Leach, Geoffrey and Golde, Helmut. "Bootstrapping XPL to an XDS Sigma 5 Computer." Software Practice and Experience 3 (1973): 235-244.
• McKeeman, William M., Horning, James J. and Wortman, David B. A Compiler Generator. Englewood Cliffs, NJ: Prentice-Hall, 1970.
• McKeeman, W. M., Horning, James J., Nelson, E.C., and Wortman, D. B "The XPL compiler generator system." AFIPS Conference Proceedings: 1968 Fall Joint Computer Conference. Washington DC: The Thompson Book Company. 1968: 617-635.
• Sitton, Gary A., Kendrick, Thomas A., and Carrick, jr., A. Gil. "The PL/EXUS Language and Virtual Machine" Proceedings of the ACM-IEEE Symposium on High-level-language Computer Architecture Nov, 1973: 124-130.
• Slimick, John "Current Systems Inplementation Languages: One User's View" Proceedings of the SIGPLAN symposium on Languages for system implementation Oct, 1971: 20-28.
• Storm, Mark W., and Polk, Jim A. "Usage of an XPL Based Compiler Generator System" Proceedings of the 14th annual ACM Southeast Regional Conference Apr, 1976: 19-26.
• Wortman, D.B. "A roster of XPL implementations." ACM SIGPLAN Notices Jan 1978: 70-74.