HTML is the fundamental building block for intranets and the web. XHTML (Extensible Hypertext Markup Language) is the newest version of HTML; it brings the functionality of XML to HTML so that developers can easily use their content on a multitude of platforms, including PDAs and cell phones. A thorough working knowledge of HTML and XHTML remains critical to effective web content development. "Mastering HTML and XHTML" is a comprehensive, up-to-date resource on these closely intertwined topics. It provides in-depth, best-practices methods for coding web and intranet sites using HTML 4.01 and XHTML 1.1.