This book is primarily a practical reference book for professional XSLT developers. It assumes no previous knowledge of the language, and many developers have used it as their first introduction to XSLT; however, it is not structured as a tutorial, and there are other books on XSLT that provide a gentler approach for beginners.

The book does assume a basic knowledge of XML, HTML, and the architecture of the Web, and it is written for experienced programmers. There’s no assumption that you know any particular language such as Java or Visual Basic, just that you recognize the concepts that all programming languages have in common.

The book is suitable both for XSLT 1.0 users upgrading to XSLT 2.0, and for newcomers to XSLT. The book is also equally suitable whether you work in the Java or .NET world.

As befits a reference book, a key aim is that the coverage should be comprehensive and authoritative. It is designed to give you all the details, not just an overview of the 20 percent of the language that most people use 80 percent of the time. It’s designed so that you will keep coming back to the book whenever you encounter new and challenging programming tasks, not as a book that you skim quickly and then leave on the shelf. If you like detail, you will enjoy this book; if not, you probably won’t.

But as well as giving the detail, this book aims to explain the concepts, in some depth. It’s therefore a book for people who not only want to use the language but who also want to understand it at a deep level.

The book aims to tell you everything you need to know about the XSLT 2.0 language. It gives equal weight to the things that are new in XSLT 2.0 and the things that were already present in version 1.0. The book is about the language, not about specific products. However, there are appendices about Saxon (the author’s own implementation of XSLT 2.0), about the Altova XSLT 2.0 implementation, and about the Java and Microsoft APIs for controlling XSLT transformations, which will no doubt be upgraded to handle XSLT 2.0 as well as 1.0. A third XSLT 2.0 processor, Gestalt, was released shortly before the book went to press, too late to describe it in any detail. But the experience of XSLT 1.0 is that there has been a very high level of interoperability between different XSLT processors, and if you can use one of them, then you can use them all.

In the previous edition we split XSLT 2.0 and XPath 2.0 into separate volumes. The idea was that some readers might be interested in XPath alone. However, many bought the XSLT 2.0 book without its XPath companion and were left confused as a result; so this time, the material is back together. The XPath reference information is in self-contained chapters, so it should still be accessible when you use XPath in contexts other than XSLT.

The book does not cover XSL Formatting Objects, a big subject in its own right. Nor does it cover XML Schemas in any detail. If you want to use these important technologies in conjunction with XSLT, there are other books that do them justice.

This book contains twenty chapters and eight appendixes (the last of which is a glossary) organized into four parts. The following section outlines what you can find in each part, chapter, and appendix.

Part I: Foundations: The first part of the book covers essential concepts. You should read these before you start coding. If you ignore this advice, as most people do, then you read them when you get to that trough of despair when you find it impossible to make the language do anything but the most trivial tasks. XSLT is different from other languages, and to make it work for you, you need to understand how it was designed to be used.

Chapter 1: XSLT in Context: This chapter explains how XSLT fits into the big picture: how the language came into being and how it sits alongside other technologies. It also has a few simple coding examples to keep you alert.

Chap