The X Window system is a software environment for engineering workstations. It was developed at the Massachusetts Institute of Technology and is now accepted by almost all workstation vendors as a standard interface to their workstation hardware.

X is highly structured. Its foundation is the base window system, which interfaces with the outside world using the X network protocol. X application programs do not use the network protocol directly. Instead, they use a C-language function package known as Xlib. A high-level X toolkit is available on top of Xlib. The toolkit masks some of the complexity of the network protocol and makes it easier for the application programmer to use.

Release 5 of the X Window system refers to the Xlib level. The manual describes the major new functionality added to both Xlib and the X toolkit: font service, scalable fonts, device-independent color, and internationalized text input and output.

The book is not meant to stand alone. It is part of a series of books on the X Window system that are available from the publisher. This work does not explain the concepts of X, and it assumes that the reader is familiar with Xlib and Xt programming in C.

The book has two main parts. One contains several independent “programmer’s manual” chapters; the other is a reference manual section that contains reference pages for each of the new functions. Together they form a complete update to volumes 1, 2, 4, and 5 of this series. Because the new capabilities of R5 are independent of one another, so are the chapters that cover them.

Font service and scalable fonts are presented in chapter2. The network font server and the X Font Service Protocol are described. Using them, a single machine at a site can be configured to provide font service to all the X servers on a local network. The font server parses the font files for any supported format and transmits font data in a bitmap format standardized by the X Font Service Protocol. Also, both the X server and the form server implement a simple font-scaling algorithm.

Chapter 3 addresses the problems of device-independent color and the X Color Management System. It describes the conversion of color names to device-independent color specifications, the new standard textual representation for device-independent color strings, and the set of Xlib functions to support this new standard representation as well as the allocation of device-independent colors.

Chapters 4 and 5 describe the largest new part of X11R5, namely the support for writing internationalized programs (those running without changes to the binary in any given locale). This means that a program displays all text in the user’s language, accepts input of all text in the same language, and so on.

A number of important changes have been made to resource management. These changes are presented in chapter6, which covers the new resource file syntax, customized resource files, screen-specific resource strings and databases, the XtNbase translations resource, and new Xrm functions.

Chapter 7 describes other changes in X11R5. As with the other chapters of the book, a sufficient number of examples complete the presentation.

The second part of the book presents reference pages for the new X11R5 Xlib and Xt functions, the new functions in the miscellaneous utilities (Xmu) library, and some other changes that are of interest to programmers. Three appendices and an index complete the presentation.

The book fulfills all the conditions one expects to find in a manual: it is precise, systematic, and explicit. As stated at the beginning, however, it is only an update intended for those familiar with X Window system and its concepts. The graphic presentation is remarkable.