XHTML or Extensible Hypertext Mark-up Language is a hybrid of XML and HTML. All pages designed in XHTML should look the same across all browsers and platforms, thanks to the way in which XHTML documents are parsed. We should be coding in XHTML, and if we do so our sites will continue to look as we intend with future evolution of the Internet with a set of global standards that everyone follows so that no-one gets left behind. XHTML also offers a streamlined and semantically rich framework that allows very clear document architecture to be established.

You can change your old HTML site into an XHTML site. Just a few common principles to follow and some minor changes to your site. Optimizing for search engines and building your site with CSS is also useful though. Making your code is readable to search engine spiders: Using XHTML to declare your main heading as H1 will ensure that a search engine spider knows that the contained text is the title of the page, while styling it with CSS yields the desired design effect. Using H1 through H6 accordingly, you can use this methodology to style the sub-headings on your website and let the search engine spiders know they are of importance.

Using Images for your SEO Benefit: An H1 tag placed directly after the tag will be weighted heavily by many search engines, especially if it contains one or two of your keywords. But sometimes, putting a nice big heading tag after your body tag can detrimentally affect your masthead image placement. Using CSS, we can work around this little hang-up in some instances by placing our masthead logo as a background. XHTML technology is bit new and it is unclear as to how the search engine spiders are viewing XHTML.

Apparently new web technology makes the job of a web designer easier and many of this is not relevant to current search engine spiders and can often be detrimental to the positioning of a web site especially when targeting extremely competitive phrases. HTML Validation: http://www.htmlhelp.com/tools/validator/ W3C Markup Validation Service: http://validator.w3.org/.