0.2.1. I Believe in Open, Platform-Neutral, Standards-Based Computing

If any part of your business life ties you down to anything closed, proprietary, or platform-specific, I encourage you to make some changes. This book shows you how to take charge of your data and move it from one place to another on your terms, not your software vendor's. XML is shifting the balance of power from software vendors to software users. If your tools force you to work in unnatural ways or refuse to let you have your data when and where you want it, you don't have to take it anymore.

0.2.2. I Assume You're Busy

This book is written for developers who want to learn how to use XSLT to solve problems. Throughout the book, we'll transform XML-tagged data into a variety of useful things. If a particular bit of arcana from the specifications doesn't relate to any practical problem I can think of, it's probably mentioned in the reference section only.

0.2.3. I Don't Care Which Standards-Compliant Tools You Use

Most examples in this book are done with Apache's Xalan XSLT engine, which is free, open source, cross-platform, and standards compliant. I use Xalan for two reasons: I've been using it longer than the others out there, and it has more developers working on it than any other XSLT engine I'm aware of. Unless otherwise stated, all examples in this book also work with Michael Kay's Saxon, Microsoft's XSLT tools, James Clark's XT, and Oracle's XML parser.

My job as an author and a teacher is to show you how to use free, standards-compliant tools to simplify your life. I'm not here to sell you a parser, an XSLT processor, a toaster, or anything else, so please use whatever tools you like. I encourage you to take a look at all of the tools out there and find your own preferences.

The XSLT processors mentioned in this book are:

Xalan

Xalan is the Apache XML Project's XSLT engine. It was originally built on the LotusXSL code base. It's available at http://xml.apache.org/xalan-j/. Every example in this book was developed and tested using Xalan. Except where noted, examples should work on all other standards-compliant XSLT processors as well, although I haven't tested other tools as thoroughly.

Saxon

Saxon was written by Michael Kay, an XSLT author and a frequent contributor to the XSLT mailing list. You can find it at http://saxon.sourceforge.net.

Microsoft's XSLT tools

As of this writing, Microsoft's XSLT processor is part of the MSXML parser, available at http://www.microsoft.com/xml. (This site seems to be redesigned frequently, so be prepared to spend some time looking. Also, there are rumors that the packaging and names of the tools may change.) The most exciting thing about this processor is that it can be integrated with the Internet Explorer browser, allowing you to transform XML documents on a client machine. By merely pointing your browser at an XML document, you can have the document transformed and rendered as HTML automatically. (For this to work, you must associate a stylesheet with the XML document. See Section 1.2.4.8, "Associating stylesheets with XML documents" in Chapter 1, "Getting Started" for more information.)

XT

XT was written by James Clark, the editor of the XSLT specification and the co-editor of the XPath specification. You can find it at http://www.jclark.com/xml/xt.html. Much of the code in XT was written to test the XSLT and XPath specs as they were developed. (Even though it is still a very popular XSLT processor, XT is no longer actively developed.)

Oracle

Oracle's XML parser is different from most because it includes the XSLT processor and the XML parser in a single package. It's free at Oracle's TechNet site (http://technet.oracle.com/tech/xml), although you do have to register before you can download it.

0.2.4. XSLT Is a Tool, Not a Religion

An old adage says that to a person with a hammer, everything looks like a nail. I don't claim that XSLT is the solution to every business problem you'll encounter. The next chapter discusses reasons why XML and XSLT were created, the design decisions behind XSLT, and tries to identify the kinds of problems XSLT is designed to solve. All chapters in this book illustrate common scenarios in which XSLT is extremely powerful and useful.

That being said, if a particular tool does something better than XSLT does, by all means, use that other tool. XSLT is a powerful addition to your tool box, but that doesn't mean you should throw out all your other tools.