HTML / XHTML / XML http://www.expandinghead.net/content/html_xml.xml Caching Tutorial http://www.mnot.net/cache_docs/ Learn about web caches and how (and how not) to control them. CoverPages http://xml.coverpages.org/xml.html Comprehensive reference collection supporting the SGML/XML family of (meta) markup language standards and their application. HTML Dog http://www.htmldog.com/ HTML and CSS Tutorials, References, Articles and News. HTML Meta Tags http://vancouver-webpages.com/META/metatags.detail.html A dictionary of HTML META tags. Usage and resources. IBM http://www-136.ibm.com/developerworks/xml/ Developer works news and columns, technical library, downloads and open source projects. index DOT html http://www.blooberry.com/indexdot/html/index.html HTML reference including historical information and browser support. MSDN http://msdn.microsoft.com/xml/ Developers center. Articles,downloads and code samples. PerfectXML http://www.perfectxml.com/ To help you learn XML technologies and use them in your applications. A collection of information on all things XML. RSS 2.0 Specifications http://blogs.law.harvard.edu/tech/rss The Really Simple Syndication content syndication format. SOAP http://www.w3.org/TR/soap/ Reference at W3. Sun http://java.sun.com/xml/ Java and XML references, downloads, tutorials and code camps. TopXML http://www.topxml.com/ Tools and XML learning tutorials. w3c http://www.w3.org/QA/2002/04/valid-dtd-list.html List of valid DTDs to use in your documents. w3c http://www.w3.org/XML/ Describes the work being done at W3C within the XML Activity, and how it is structured. w3schools http://www.w3schools.com/html/html_reference.asp HTML 4.01 Reference. w3schools http://www.w3schools.com/html/default.asp HTML tutorial. w3schools http://www.w3schools.com/xhtml/default.asp XHTML tutorial. w3schools http://www.w3schools.com/xml/default.asp XML tutorial and examples. w3schools http://www.w3schools.com/dom/default.asp XML Dom reference. w3schools http://www.w3schools.com/xsl/ XSLT extensible stylesheet language tutorial. WDVL http://wdvl.internet.com/Authoring/HTML/4/Tags/ 4.0 tag and attribute reference. WSDL http://www.w3.org/TR/wsdl Reference at W3. XML-RPC http://www.xmlrpc.com/ Cross-platform distributed computing, based on the standards of the Internet. XML.com http://www.xml.com/ From the inside out at O'Reilly. Articles, news and resources. XMLfiles http://xmlfiles.com/ Extensible markup language tutorials for developers. XMLHack http://www.xmlhack.com/ News, opinions, tips and issues concerning XML development.