At various levels of standardization: XML Namespaces; CSS Level 1; CSS Level 2; HTML 4.0; XHTML 1.0; XSL Formatting Objects; XSL Transformations 1.0; XPath 1.0; XML Schema Part 0: Primer; XML Schema Part 1: Structures; XML Schema Part 2: Datatypes; XLinks; XPointers; XLink Design Principles; SOAP; XML Data; XMLR Query Language; Minimal XML; DOM; SAX; Document Content Description (DCD) for XML; URLs; URIs; Dublin Core