What Are Open Systems?

Ben Smith

OPEN SYSTEMS: THE REALITY by Terry A. Critchley and K. C. Batty, Prentice-Hall, ISBN 0-13-030735-1, $40

As Critchley and Batty demonstrate at the beginning of their book Open Systems: The Reality, the one thing that seems too open is the definition of the phrase open systems. The definition that you receive may be nothing more than a rephrasing of "Buy our system; we are open for business." But as the authors point out, actual standards have been written that specify what open systems can mean in a valuable way.

This book traces the history of each standard and organization. It also gives an overview of what each standard involves. Of particular note is the history and charter of X/Open and the OSF (Open Software Foundation). Now that the Unix trademark is controlled by X/Op en, there will be more pressure to move to Unix certification rather than just being satisfied with Posix compliance. Open Systems: The Reality is written for information systems managers as well as the technical people who plan on implementing edicts for open systems. It provides an overview of the subject while still providing enough technical content that you can understand the differences between competing standards.