Books about XML: Printed books on XML are out of date almost before they reach bookstore shelves. Still there's no shortage of XML books being published (approaching 100 to date). Below is a list of my personal favorites. For more titles see http://www.oasis-open.org/cover/biblio.html and http://www.xmlbooks.com/

• Eckstein, Robert (1999). XML Pocket Reference , O'Reilly (ISBN: 1565927095). Brief but handy quick reference to XML and XSLT by an author with considerable experience and success writing about Web technologies.

• Goldfarb, Charles F. and Paul Precod (2000). The XML Handbook , 2^nd edition, Prentice Hall PTR (ISBN: 0130147141). Not primarily a tutorial. Focuses more on possible XML implementations than on the rules of XML. Included partly in recognition that Goldfarb was the primary author of SGML.

• Gulbransen, David (2000). Complete Idiot's Guide to XML , Macmillan (ISBN: 0789723115). A fine, more introductory tutorial on XML.

• Harold, Elliotte Rusty (1999). XML Bible , IDG Books Worldwide (ISBN: 0764532367). Slightly out of date now, but still one of the better (and longer) tutorials on XML. XML only, little in the way of XML programming.

• Kay, Michael (2000). XSLT Programmer's Reference , Wrox Press (ISBN: 1861003129). An expert tutorial on XSLT.

• Marchal, Benoit (1999). XML by Example , Que/Macmillan (ISBN: 0789722429). A very readable introduction to XML for the technically oriented. Be advised there's another, very different book with the same title.

• Mohr, Stephen, editor (2000). Professional XML , Wrox Press (ISBN: 1861003110). An advanced tutorial and "how to do it right" book with contributions from a large collection of XML experts.

• Morrison, Michael (1999). XML Unleashed , Sams/Macmillan (ISBN: 0672315149). A comprehensive (sometimes too comprehensive) reference for XML.

• Pardi, William J. (1999). XML in Action , Microsoft Press (ISBN: 0735605629). Good on the basics and useful if you plan to implement XML using Microsoft parsers and Microsoft Internet Explorer.

XML resources on the web: Because XML is still evolving, the Web is still the best way to keep current on this topic. These are among the most important XML sites.

• http://www.w3.org/XML/
  XML is an output of the World Wide Web Consortium (W3C), and this is Home Page URL for the W3C's XML effort.

• http://www.oasis-open.org/cover/sgml-xml.html
  From the earliest days of the Web, Robin Cover has had the overall best website for SGML, and more recently for SGML and XML together. This site is hosted by OASIS, the Organization for the Advancement of Structured Information Standards.

• http://www.legalxml.org/
  This is the home page for LegalXML, a non-profit, volunteer organization hosted by Georgia State University. The mission of LegalXML is develop open, non-proprietary technical standards for legal documents and related applications. LegalXML is working closely with general legal organizations (notably the ABA, COSCA, and NACM) on XML standards (e.g., see: http://www.courtxml.org/xml/JjntXmlStandard.nsf?opendatabase).

• http://www.xml.com/
  More commercial than most of the others on this list, this site is still a rich resource for XML information. The site is a collaborative partnership between Seybold Publications and Songline Studios, an affiliate of O'Reilly & Associates.

• http://www.xml.org/
  Billing itself as "The XML Industry Portal," this is a 2^nd XML site sponsored by OASIS. Slightly less commercial looking than xml.com.

• http://www.mulberrytech.com/quickref/index.html
  A couple of great quick reference guides to XML and XSL, suitable for printing.

• http://msdn.microsoft.com/workshop/xml/index.asp
  Microsoft has been among the early adopters of XML. Though some purists continue to be concerned about Microsoft-specific XML and XSLT extensions, Microsoft maintains one of the more informative websites on XML as well as having some of the better XML applications and implementations.

• http://java.sun.com/xml/
  If you're more in the Java camp, this is better site. Links to a lot of useful Java-based XML tools as well as to general information about XML.

• http://www.ibm.com/developer/xml/
  If you eschew both Windows and Java, try this site.

• http://www.jclark.com/
  James Clark has been a leader in the SGML and XML communities since 1991 and has created and made available some of the best generic (and free) SGML and XML software.

• http://www.xmlbooks.com/
  Charles F. Goldfarb is recognized as the primary author of SGML. His site is an annotated XML bibliography. He also maintains an SGML home page at http://www.sgmlsource.com/index.htm

• http://www.xmetal.com/
  Home page for the XMetal XML authoring tool. A commercial XML product from SoftQuad that functions a lot like a word processor for XML. See also SoftQuad's home page at http://www.softquad.com/

• http://www.extensibility.com/
  Home page of another commercial XML tool vendor. Extensibility's XML Authority tool can be used to generate XML schemas and DTDs.

• http://www.vervet.com/
  Home page for the company that produces XML Pro, an inexpensive XML authoring tool.

• http://www.arbortext.com/
  Home page Arbortext, who sell a wide range of SGML and XML tools, including the Adept XML/SGML authoring software.