What is XHTML?
XHTML stands for eXtensible HyperText Markup Language.
XHTML is a strictly write in case-sensitive opening or closing tags.
XHTML documents need to be well-formed and application of the XML.
XHTML is a W3C Recommendation because XHTML is a strictly clean and well-formed.
What is need to create HTML?
You don't need to use any special software to develop. only you have need a text editor or HTML editor application are need.
If you want to use best HTML Editor is What You See Is What You Get (WYSIWUG) like Microsoft FrontPage and Adobe Dreamweaver CS5 or latest. In this two Software are good for coding an web programming.
Text base Editor is a Simple syntax highlighter editor that help to tags opening closing simple limited help give like UltraEdit, Notepad++, TextPad etc.
HTML tags keywords are surrounding in Opening Tag <html> and Closing Tag</html>.
HTML tags is pairs like <body> and </body>. It's container tags.
Some HTML tags is not pairs in Opening and Closing like <br />, <hr />. It's empty tags.
All tags are write in Lower Alphabetical and empty tags always write in closing Tag type like <br />.
XHTML is a Recommendation of W3C
XHTML 1.0 became a World Wide Web Consortium (W3C) Recommendation on January 26, 2000.
XHTML 1.1 became a W3C Recommendation on May 31, 2001.
XHTML5 is undergoing development as of September 2009, as part of the HTML5 specification.
XHTML with DHTML technologies
DHTML allows scripting languages to change variables in a web page's definition language, which in turn affects the look and function of otherwise "static" XHTML page content, after the page has been fully loaded and during the viewing process. Thus the dynamic characteristic of DHTML is the way it functions while a page is viewed, not in its ability to generate a unique page with each page load.