There's little doubt that XML (Extensible Markup Language) is among the emerging technologies that will gain a wide and significant acceptance. In particular, this means that companies will be writing real-world applications and services based on it. Why? Because XML is a powerful tool when designing Web applications and a universal data format to marshal information across the various tiers of the system. XML describes data, no matter the language, platform, or format. This principle emerges clearly from XML Applications, by Frank Boumphrey et al. This is the first book that tries to bring XML to a wide audience by explaining how to take advantage of it in your own projects.
There's good and bad with the book. The good point is that the book works well as an overall reference to XML. It covers in detail the language, metadata, structure, stylesheets, current standards, and important in-progress proposals (such as XLinks and XPointers). It also provides useful links to web sites.
On the other hand, XML Applications does not make clear why and when you should resort to XML. Because it's cool and exciting? Perhaps. Do you have to turn your system inside out in the name of XML? Do you have to write your XML-enabled browser or plug-in? Do you have to forget about HTML? Answers to these and other questions are scattered throughout the book, but aren't specifically spelled out anywhere. In other words, the book is somewhat poorly organized and doesn't live up to the claim in the introduction that "no experience of XML is assumed."
The first three chapters cover the basic knowledge of XML: well-formed documents, document type definitions, and schemas. Next, you are introduced to namespaces and concepts such as links and pointers. The W3C XML document object model is discussed in Chapter 6, followed by the XML Style Sheet that demonstrates at last how the separation between data and presentation occurs. The final chapter presents examples of using XML on the server-side as the mainstream of data managed by some ASP pages.
XML Applications presents itself as a review of the applications you could create with XML, but isn't convincing enough as for when and why you might need to do so. That doesn't mean, though, that the authors aren't right! In the authors' defense, I'd guess that the book suffered from the lack of released browsers or fully XML-enabled tools. With the availability of Internet Explorer 5.0, for instance, the book might have been organized differently.
In summary, XML Applications is a useful language reference. However, it is far less helpful as a guide to create real-world applications.
Electronic Review of Books