XML (Extensible Markup Language) allows Web developers to enhance database connectivity, enrich pages with specialized data elements, and otherwise move beyond the limitations of HTML. This highly visual tutorial demonstrates over 100 different XML operations, from formulating Document Type Definitions (DTDs) to setting up styles with Extensible Stylesheet Language (XSL). The CD-ROM contains code examples and an e-version of the book.
As I recall this was a guide introductory guide to XML for beginners. Not sure how well it has aged, as of 2013 it is well over 10 years old which is an eternity in the tech space for certain topics.