XHTML 1.0 Combines the Familiarity of HTML with the Power of XML

The real benefit of moving to XHTML is a longer-term one than having new gizmos to play with. HTML has been stretched way beyond it's original design goals, by browser manufacturers who were more interested in proprietary advantage than standards.

Also, the language was not that good in the first place, but it served brilliantly to ignite the web (as did some of those browsers). Much has been learnt, and now we have a new meta-language - XML - within which to define new language applications for the web. XHTML is one of them. The benefit to you, as a web developer, is in the move towards XML.

XHTML will be most suitable to the construction of new sites where you would like to drop legacy baggage such as the intertwining of content and presentation in HTML, and you want to be well-prepared to move into the 21st century web.

XHTML 1.0 allows authors to create Web documents that work with current HTML browsers and that may be processed by XML-enabled software as well. Authors writing XHTML use the well-known elements of HTML 4 (to mark up paragraphs, links, tables, lists, etc.), but with XML syntax, which promotes markup conformance.

W3C provides instruction and tools for making the transition from HTML 4 to XHTML 1.0. The "HTML Compatibility Guidelines" section of the XHTML 1.0 Recommendation explains how to write XHTML 1.0 that will work with nearly all current HTML browsers. W3C offers validation services for both HTML and XHTML documents. W3C's Open Source software Tidy helps Web authors convert ordinary HTML 4 into XHTML and clean document markup at the same time.

Introduction to XHTML: Why do we need XHTML?
Introduction to XHTML, with eXamples
XHTML 1.0 Provides a Foundation for Device-Independent Web Access