The REXX Language
A Practical Approach to Programming


  • Summary of the Rexx Language
  • Fundamental Language Concepts
  • Language Overview and Examples
  • Design Principles
  • History
  • Complete Language Definition for Rexx 4.00
  • Syntax diagrams
  • etc.
The Rexx Language is available from Prentice Hall,, or from your local bookshop. Here are the details for ordering:

The REXX Language, M. F. Cowlishaw
ISBN 0-13-780651-5, 203pp, Prentice Hall, 1990 (second edition)

About the book...

Rexx is the programming language designed for people, not machines. It swept IBM when it was first distributed on IBM’s internal network by its creator. With heavy use by a lively networking community it has evolved to meet the needs of its users. In 1987, IBM acknowledged its success and adopted it as one of the cross-system SAA (Systems Application Architecture) languages.

Now Rexx has spread outside IBM, on both mainframes and micros. Today, more than six million people have Rexx on their systems. One scientific laboratory has over four million lines of Rexx programs. There are Rexx implementations for the VM, MVS, OS/2, and PC-DOS operating systems, with more on the way, and there is now a Rexx compiler.

Rexx provides modern features such as arbitrary precision decimal arithmetic, natural data typing, symbolically indexed arrays, and powerful built-in string parsing functions – features not available in languages designed in the fifties and sixties, such as FORTRAN and BASIC.

In this book, Mike Cowlishaw defines the language he has designed and also explains the principles that shaped it. In line with the Rexx philosophy, the book has been revised in response to users’ comments. This second edition includes the definition of version 4.00 of the Rexx language, together with background information and a new glossary.    (From the back cover, 1990.)

The first edition (ISBN 0-13-780735-X) was published in 1985, and was also published in German (ISBN 3-446-15195-8, Carl Hanser Verlag, 1988) and in Japanese (ISBN 4-7649-0136-6, Kindai-kagaku-sha, 1988).

IBM's Rexx page can be found at:
Lots of information about the history of Rexx can be found at:

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