Below is a list of XML-related technologies.
DTD (Document Type Definition) is used to define the legal elements in an XML document.
XSD (XML Schema) is an XML-based alternative to DTDs.
XHTML (Extensible HTML) is a stricter and cleaner version of HTML.
XSL (Extensible Style Sheet Language) - XSL consists of three parts: XSLT - a language for transforming XML documents, XPath - a language for navigating in XML documents, and XSL-FO - a language for formatting XML documents.
XSLT (XSL Transformations) is used to transform XML documents into other XML formats, like XHTML.
XML DOM (XML Document Object Model) defines a standard way for accessing and manipulating XML documents.
XPath is a language for navigating in XML documents.
XSL-FO (Extensible Style Sheet Language Formatting Objects) is an XML based markup language describing the formatting of XML data for output to screen, paper or other media.
XLink (XML Linking Language) is a language for creating hyperlinks in XML documents.
XPointer (XML Pointer Language) allows the XLink hyperlinks to point to more specific parts in the XML document.
XForms (XML Forms) uses XML to define form data.
XQuery (XML Query Language) is designed to query XML data.
SOAP (Simple Object Access Protocol) is an XML-based protocol to let applications exchange information over HTTP.
WSDL (Web Services Description Language) is an XML-based language for describing web services.
RDF (Resource Description Framework) is an XML-based language for describing web resources.
RSS (Really Simple Syndication) is a format for syndicating news and the content of news-like sites.
WAP (Wireless Application Protocol) was designed to show internet contents on wireless clients, like mobile phones.
SMIL (Synchronized Multimedia Integration Language) is a language for describing audiovisual presentations.
SVG (Scalable Vector Graphics) defines graphics in XML format.