Editing XML Schema (W3C) (section)

==History==
'''XML Schema''', published as a [[W3C recommendation]] in May 2001,<ref>{{cite web|url=http://www.dblab.ntua.gr/~bikakis/XML%20and%20Semantic%20Web%20W3C%20Standards%20Timeline-History.pdf |title=XML and Semantic Web W3C Standards Timeline
|date=2012-02-04}}</ref> is one of several [[XML schema|XML schema languages]]. It was the first separate schema language for [[XML]] to achieve Recommendation status by the W3C. Because of confusion between XML Schema as a specific W3C specification, and the use of the same term to describe schema languages in general, some parts of the user community referred to this language as '''WXS''', an initialism for W3C XML Schema, while others referred to it as '''XSD''', an initialism for XML Schema Definition.<ref>See [http://www.w3.org/standards/xml/schema Schema - W3C]</ref><ref>See [http://www.w3.org/TR/xmlschema11-1/ W3C XML Schema Definition Language (XSD) 1.1 Part 1: Structures]</ref> In Version 1.1 the W3C has chosen to adopt XSD as the preferred name, and that is the name used in this article.

In its appendix of references, the XSD specification acknowledges the influence of [[Document Type Definition|DTD]]s and other early XML schema efforts such as [[DDML]], [[Schema for Object-Oriented XML|SOX]], XML-Data, and [[XDR Schema|XDR]]. It has adopted features from each of these proposals but is also a compromise among them. Of those languages, XDR and SOX continued to be used and supported for a while after XML Schema was published. A number of [[Microsoft]] products supported XDR until the release of [[MSXML]] 6.0 (which dropped XDR in favor of XML Schema) in December 2006.<ref>{{cite web|url=http://msdn.microsoft.com/en-us/library/ms761410%28v=VS.85%29.aspx|title=Removal of XDR Schema Support in MSXML 6.0|access-date=2010-09-19}}</ref> [[Commerce One]], Inc. supported its SOX schema language until declaring bankruptcy in late 2004.

The most obvious features offered in XSD that are not available in XML's native [[Document Type Definition]]s (DTDs) are [[XML Namespace|namespace]] awareness and datatypes, that is, the ability to define element and attribute content as containing values such as integers and dates rather than arbitrary text.

The XSD 1.0 specification was originally published in 2001, with a second edition following in 2004 to correct large numbers of errors. XSD 1.1 became a [[World Wide Web Consortium#W3C recommendation (REC)|W3C Recommendation]] in [http://www.w3.org/News/2012#entry-9412 April 2012].