M is an interesting programming language for two main reasons. First, it is a relatively old language, its first incarnation being the MUMPS language created at the Massachusetts General Hospital in 1967. Second, it is one of a few high-level languages for which there is an ANSI standard. Despite this and other assets, M is little known outside of its user community, which traditionally has been the medical and health communities. For example, M is currently  being  used for the Department of Defense’s multibillion-dollar Comprehensive Health Care System project.

M is mostly a procedural interpreted language, with language-specific features for handling large data files. The language has gone through three ANSI standard reviews, in 1984, 1990, and 1995. For readers seeking more information, the author mentions the M Technology Association, located in Silver Spring, Maryland (301-431-4070).

The book’s 25 chapters are organized into two parts, as follows:

Part 1: M for the Novice Programmer

• A Brief Introduction to Computers

• Introduction to M

• Basic Components of M

• Operations on Number Values

• Logical Operators, Comparisons

• Operations on Strings

• Introduction to M Commands

• Command Lines and Conditional Tests

• Routine Structure and Execution Flow Control

• Program Structure

• Local Arrays

• Global Variables

• External Communication: Files and Devices

• Some Special Features of M

• Indirection: Dynamic Reference Modification for Execution Control and Data Management

• Access Control of Local Variables

• Implementation-Specific Components of M

• An Applications Example: A Course Grading Package

Part 2: M for the Experienced Programmer

• (19)Overview of M for Experienced Programmers

• (20)Distributed Systems: Multitasking and Multiuser M (Networks, Locks, Transaction Processing, and More)

• (21)Interacting with the Operating System (Structured System Variables, Internationalization, and More)

• (22)Interfacing M to Other Standards (SQL, GKS, X Windows)

• (23)M and [Microsoft] Windows Environments

• (24)Error Handling in M

• (25)Looking into the Future

The book is well written, and each chapter contains many examples illustrating various language constructs. The author lists several Web sites (p. 16) where more information on M and software is available. It would be nice if the book included a disk with an M interpreter and some source code examples. Like Forth, LISP, and Ada, the language will never grow beyond its niche. Nevertheless, for those using or trying to learn the language, this is a nice book to have on hand.