The web site http://www.xml.com is one of the most complete and timely sources of XML information and news around. It should be on your weekly reading list if you are learning or using XML.

Sponsored by OASIS, http://www.xml.org has XML news and resources, including the XML Catalog, a guide to XML products and services.

Edited by Robin Cover, http://xml.coverpages.org/ is one of the largest and most up-to-date lists of XML resources.

Elliotte Rusty Harold provides almost daily news, along with a quote of the day, at http:// ibiblio .org/xml.

For programmers itching to work with XML, http://www.xmlhack.com is a good place to go for news on the latest developments in specifications and tools.

OASIS, the maintainers of DocBook, have a web page devoted to the XML application at http://www.docbook.org/. You can find the latest version and plenty of documentation here.

Jukka Korpela has assembled a huge amount of information related to character sets at http://www.cs.tut.fi/%7Ejkorpela/. The tutorial is well written and very interesting reading.

Signing up with the XSL mailing list is a great way to keep up with the latest developments in XSL and XSLT tools and techniques. It's also a forum for asking questions and getting advice. The traffic is fairly high, so you should balance your needs with the high volume of messages that will be passing through your mailbox. To sign up, go to http://www.mulberrytech.com/xsl/ and follow the instructions.

The xml-dev mailing list is an extremely busy forum for discussion of all kinds of XML-related issues and best practices. To sign up, go to http://lists.xml.org/ and follow the instructions.

This part of the Apache project focuses on XML technologies and can be found at http://xml.apache.org. It develops tools and technologies for using XML with Apache and provides feedback to standards organizations about XML implementations .

This guide is the Microsoft Developers Network's online workshop for XML. It contains information about using XML with Microsoft applications and can be found at http://msdn.microsoft.com/xml/XMLGuide/.

This journal contains articles, resources, opinions , news, and reviews covering all aspects of programming. Go to http://www.ddj.com for online content, and subscribe to the magazine while you're there.

Perl is an interpreted programming language for any kind of text processing, including XML. The best place online for information or to download code and modules is http://www.perl.com.

The best source for Java news and information is http://www.javasoft.com. Java is a programming language available for most computers and contains a lot of XML support, including implementations of SAX and DOM, as well as several great parsers.

A comprehensive desktop reference for all things XML.

A solid introduction to XML that provides a comprehensive overview of the XML landscape.

A timely and comprehensive resource for learning about HTML.

A step-by-step tutorial for designing and implementing DTDs. While this book is about SGML, much of its advice is still excellent for XML.

A complete reference for SGML, including an annotated specification. Like its subject, the book is complex and hefty, so beginners may not find it a good introduction.

A guide to combining XML and Java to build real-world applications.

A complete guide to using the SAX2 API, in Java.

A guide to building programs using a variety of Java techniques for processing XML.

Explores many different aspects and APIs of Java processing with XML.

A guide to processing XML with data-binding approaches, covering APIs which insulate developers from the XML.

A guide to processing XML with a variety of Perl-based approaches.

A guide to processing XML in Python programs.

A guide to processing XML using the Microsoft .NET API.

A detailed look at Oracle tools for XML development, and how to combine the power of XML and XSLT with the functionality of the Oracle database.

DocBook is a popular and flexible markup language for technical documentation, with versions for SGML and XML. This book has an exhaustive, glossary-style format describing every element in detail. It also has lots of practical information for getting started using XML and stylesheets.

Explores W3C XML Schema in depth, using many examples to illustrate usage.

A thorough explanation of the W3C XML Schema specification and usage.

A thorough explanation of RELAX NG, including both theory and practice.

A carefully paced introduction to XSLT development.

A tutorial for XSLT, focusing on simple and largely HTML-based examples.

A guide to XSLT development, from the basics to advanced features.

A reference guide for XSLT development, including techniques and best practice.

A tutorial and reference for XSLT development.

An exploration of advanced XSLT and XPath techniques.

An introduction to the XPath and XPointer specifications for addressing parts of XML documents.

An introduction to XSL Formatting Objects, covering page layout techniques and stylesheet integration.

Explores many different aspects and APIs of Java processing with XML.

An introduction to the world of Web Services.

An introduction to the Web Services specifications, including XML-RPC, SOAP 1.1, WSDL, and UDDI.

A guide to using web services in a Perl environment.

A complete guide to the Blocks Extensible Exchange Protocol, an IETF effort built on XML.

A guide to working with Jabber, an instant messaging program and protocol built on XML.