XML: Extensible Markup Language

The Extensible Markup Language is a strict serialization of the Document Object Model.

EXSLT

EXSLT is a set of extensions to XSLT. There are a number of modules; those that are supported by Firefox are listed below:

XML Guides

This page lists guides for XML.

XPath

XPath stands for XML Path Language. It uses a non-XML syntax to provide a flexible way of addressing (pointing to) different parts of an XML document. It can also be used to test addressed nodes within a document to determine whether they match a pattern or not.

XSLT: Extensible Stylesheet Language Transformations

Extensible Stylesheet Language Transformations (XSLT) is an XML-based language used, in conjunction with specialized processing software, for the transformation of XML documents.