XML

As long as only well-formedness is required, XML is a generic framework for storing any amount of text or any data whose structure can be represented as a tree. The only indispensable syntactical requirement is that the document has exactly one root element (alternatively called the document element). This means that the text must be enclosed between a root start-tag and a corresponding end-tag.

XPath

XPath may be used to compute values (strings, numbers, or boolean values) from the content of an XML document.

• XPath tutorials
• XPath tools