An XML Schema Language is a method for specifying a
Grammar or rules for a class of
XML documents. Even though the
XML standard itself already contains such an XML Schema Language (the
DTD), this XML Schema Language has a number of shortcomings, most notably no type derivation, and almost no support for data types. Consequently, a number of XML Schema Languages have been proposed, which aim at providing a more powerful language for specifying
Grammars for
XML documents.
W3C's
XSD is the most promising prospect for becoming the XML Schema Language to replace
DTDs.