XML is a new technology designed to simplify the transmission of structured documents over the Web. This reference book is intended for anyone concerned with Internet and intranet applications: programmers, designers of information systems, and specialists in the production and dissemination of documents on the Web. It will interest readers with various levels of experience, and though it is not introductory, the authors assume only that readers are familiar with how the Internet works without XML.

The book is divided into five parts, plus an index. An accompanying CD-ROM contains interesting XML applications, with source code (most of which are discussed in the book); stylesheets; XML tools; Sun’s Java Development Kit; and full source code for all the projects presented in the book. There is sufficient material on this CD to enable readers to begin developing XML applications.

Part 1 (chapters 1 through 3) presents the XML universe--internets, XML and SGML, structured documents, data-driven architecture, and XML and SGML tools. It is a good introduction to the techniques needed to design an XML application, which are presented in the rest of the book.

The next three parts present three projects implemented using XML and Java. Part 2 (chapters 4 through 8) consists of an introduction to Perl and XML followed by examples of the design and implementation of four applications: a bulletin board, a customer contact database, an XML search engine, and transformation filters. Some code examples are given in both XML and HTML. This useful section clarifies specific Internet terms, concepts, and standards.

Part 3 (chapter 9) presents an SGML/XML email application written in Perl and C++. This part also clarifies such subjects as entity management, catalogs, MIME, and SGML and XML parsing.

Part 4 (chapter 10) presents general information on XML parsers and the APIs through which developers access them. It also covers a project that builds an application based on the Document Object Model and using a Java XML parser API. The Java code examples are poorly commented.

Finally, Part 5 (chapter 11) discusses the role of XML in software architectures and presents negotiation agents and negotiation problems.

Unfortunately, the index is poor, and there is no appended list of XML specifications.

In presenting the material by working through projects, the authors gain readers’ interest. Accordingly, readers encounter concrete problems and solve them with the help of the information supplied in the book, which fulfills its basic purpose as a guide to building XML Internet applications. I recommend it because it provides insight into the potential of XML.