ABSTRACT
XML (eXtensibleMarkup Language) (W3CXML 2008) has become the de facto standard for information exchange over the World Wide Web. An XML document can define its own tags (and hence called extensible); this is unlike HyperText Markup Language (HTML), where the tags are predefined and specify formatting information. For instance, XML is used as the basis for Simple Object Access Protocol (SOAP) (W3C SOAP 2007) that is used in web services and allows applications to communicate over the Internet; XML is used in Mathematical Markup Language (MathML) (W3C MathML 2010) that allows mathematical notations and content to be processed by web applications.
