ABSTRACT
The Extensible Markup Language XML is a fundamental data format for the World Wide Web which is widely in use. It is recommended by the World Wide Web Consortium (W3C) for data exchange and electronic publishing. In this appendix we briefly review those parts of the XML specification which we need in this book, and a little bit more in order to convey an intuition about XML. It is not a complete introduction: For an in-depth study, see the documents provided by the W3C,1 or any of the numerous books on XML and XML Schema which you can find in your bookshop or your library.
