CHAPTER
INTRODUCTION TO XML AND ITS APPLICATIONS
Laura Papaleo
Department of Informatics and Computer Science, University of Genova
Via Dodecaneso, 35 16100 Genova, Italy
E-mail: [email protected] – [email protected]
Extensible Markup Language (XML) is a meta-language for defining new
languages. Its impact on the modern and emerging web technologies has been
(and will be) incredible and it has represented the foundation of a multitude of
applications. This chapter is devoted to the presentation of XML and its
applications. It provides an introduction to this wide topic, covering the
principal arguments and providing references and examples.
1. Introduction
XML is hugely important. It has been defined as “the holy grail of computing,
solving the problem of universal data interchange between dissimilar systems”
(Dr. Charles Goldfarb). XML is basically a handy format for everything from
configuration files to data and documents of almost any type. The first version of
XML became a W3C Recommendation in 1998, while its fifth edition has been
declared recommendation last year, in 2008 [1].
XML is significant, but it is a hard subject to describe briefly in a chapter,
because it describes a whole family of technologies and specifications. In 10
years, its success has been incredible and it has represented the foundation of a
multitude of applications.
This chapter has the goal to present the XML meta-language, trying to give an
overview of the most significant parts. We will describe the syntax to create
XML documents and how we can structure them by defining specific grammars
(DTDs and XML Schemas). We will also show how to render XML documents
using CSS style sheets and how to transform and render them with a family of
XML-based languages (XSL, XSLT and XPath). The end of the chapter will be
dedicated to provide a snapshot of the “life” around XML, to let the reader
understand the immense impact of XML in the actual technological world.