HTML Home Page - The W3C's HTML website, including information about HTML and XHTML.
XHTMLguru.com - Rapid introduction to the new XHTML specification.
Mozquito - Set of XHTML tools includes an XHTML-FML (Forms Markup Language) authoring environment, and viewer which transforms the extended tags into HTML and JavaScript.
XHTML.org - A large source of information, with news and books about XHTML.
The Emperor Has New Clothes - A thorough introduction to XHTML as a rebirth of HTML under XML. Discusses practical issues of XHTML use.
Extending XHTML - A laypersons guide to extending XHTML,along with discussions on XHTML's future.
XDG: XHTML Design Guide - Introduction, tutorial, standards documents, and links to articles.
The HTML Writers Guild - Details the main differences between HTML and XHTML.
