Web Standards Programmer's Reference: HTML, CSS, JavaScript®, Perl, Python®, and PHP

Chapter 11. XML

The Extensible Markup Language (XML) is a popular scheme for representing data. Although created as a more portable version of SGML, XML lives mostly on the application side of the computer world. XML is used to store preferences and data from applications, provide unified data structure for transferring data, encapsulate syndicated feeds from Web sites, and more. The XML standards are being adopted by other data formats such as HTML (creating XHTML).

This chapter presents a primer on XML, including its format, methods, and tools.

Full coverage of XML is outside the scope of this book—full coverage of XML can occupy an entire book of its own. In the case of the Web, XML is a bystander technology, useful to know but not entirely critical for publishing on the Web. However, because XHTML is XML compliant, coverage is mandatory. If you desire more information about XML, you would do well to pick up a book dedicated to the subject, such as WROX Beginning XML, 3rd Edition, WROX XSLT 2.0 Programmer's Reference, 3rd Edition, or Wiley's XML Weekend Crash Course or XML Programming Bible.