eXtensible Markup Language (XML)

The World Wide Web Consortium's (W3C's) XML Working Group developed XML (Extensible Markup Language) in 1996. It is related to the Standard Generalised Markup Language (SGML) and is a widely supported open technology for data exchange, that is, it is non-proprietary.

XML documents only contain data and not formatting instructions, so the application processing it, such as a web browser, may render it in a different way. In fact different web browsers can also display the data in different ways too. XML elements describe the semantics of the data; an element may have attributes to provide additional information. An element itself can have a sequence of nested sub-elements and the sub-elements may themselves be tagged elements or character data.

XML-Processing programs can search, sort manipulate and render XML documents such as above, using technologies such as the Extensible Stylesheet Language (XSL). Later versions of some web browsers have built-in support for displaying XML data, but can render them differently as will be seen if you try the examples below using different browsers.

XML documents are highly portable, viewing or modifying an XML document does not require any special software - NotePad or any text editor is sufficient. The XML document typically has an .xml file extension. One important characteristic of XML is that it is both human and machine-readable

Useful websites:

XML Examples:

Simple Hobbies example Source Execute
Hobbies example with stylesheets Source Execute