What is XHTML?
Learn about the changes in HTML 4.0 and how it relates to XHTML 1.0. By Jennifer Kyrnin, your About Guide to HTML.
Definition of XHTML
What does XHTML mean? A definition. From the HTML/XML Glossary on About.
Modules are an integral part of XHTML. They are a way to define the different aspects of XHTML and provide user-agent support.
What are all Those "MLs"?
SGML, XML, HTML, SM(i)L, MathML, etc. What are all these things? How do they relate? From Jennifer Kyrnin, your HTML/XML Guide.