XML schema languages: beyond DTD
Demetrios Ioannides · Library Hi Tech · 2000
The flexibility and extensibility of XML have largely contributed to its wide acceptance beyond the traditional realm of SGML. Yet, there is still one more obstacle to be overcome before XML is able to become the evangelized universal data/document format. The obstacle is posed by the limitations of the legacy standard for constraining the contents of an XML document. The traditionally used DTD (document type definition) format does not lend itself to be used in the wide variety of applications XML is capable of handling. The World Wide Web Consortium (W3C) has charged the XML schema working group with the task of developing a schema language to replace DTD. This XML schema language is evolving based on early drafts of XML schema languages. Each one of these early efforts adopted a slightly different approach, but all of them were moving in the same direction.