Because the topic is changing so quickly, it is difficult to publish a current book on XML. Even with this disadvantage, the book gives the reader the information needed to understand how XML works, what its potential is, and generally how to implement it. I have two negative comments:1. The book is a too cursory with emerging technologies which will be the mainstay of the technology: DOM, XSL, XSLT, SAX. These parts are critical for implementors and should have been discussed more thoroughly.2. For a book on markup, they should have gotten the table of contents marked up correctly.On the whole, an excellent book. Very readable.