Resources

The following web sites provide useful XML information:

• The XML Cover Pages, which provides very comprehensive information about XML.
• XML.COM
• XMLSoftware.com
• Charles F. Goldfarb's All the XML Books in Print
• Frequently Asked Questions about XML
• The W3C web site (XML and XSLT are W3C standards)
• XML Articles and Tutorials
• marchal.com (XML articles and newsletter)
• The Zvon Tutorials, which are on-line tutorials on XML, XSLT, DTD, etc.
• eXtensinet.com Global Resource Network (XML and WAP resources)
• THE ONE STOP XML RESOURCE CENTER
• Microsoft's XML Developer Center
• XMLephant
• xmlpitstop.com

You might find the following XML-related resources interesting, even though they are bit theoretical:

• Robert Lyons wrote an article entitled The Difficulty of Schema Conformance Problems; it was published on August 4, 2003.

  The article examines the difficulty of the schema conformance problem for the following XML schema languages:

  • DTD
  • RELAX NG with W3C XML Schema Datatypes
  • Schematron
  • W3C XML Schema
  • Namespace Routing Language

  The schema conformance problem is defined as follows: Given a schema, is there an XML document that conforms to the schema?

  For these five XML schema languages, the schema conformance problem is intractable (ranging from NP-hard to undecidable).

  There is also an earlier version of the article.

• The TMML Home Page, which describes the Turing Machine Markup Language (TMML) and a TMML interpreter written in XSLT.