The W3C XHTML2 Working Group has released of XHTML Modularization 1.1 . "This modularization provides a means for subsetting and extending XHTML, a feature needed for extending XHTML's reach onto emerging platforms. This specification is intended for use by language designers as they construct new XHTML Family Markup Languages. This specification does not define the semantics of elements and attributes, only how those elements and attributes are assembled into modules, and from those modules into markup languages. This second version of this specification includes several minor updates to provide clarifications and address errors found in the first version. It also provides an implementation using XML Schemas."