I have a website written in HTML5, and the same website written in XHTML. I would like to render one or the other based on whether or not someone is using a browser that supports some of the most basic features of HTML5.
The site does not use the canvas, audio, or video features of HTML5. It is simply tagged with aside, section, nav, etc, and uses some of CSS3's fun features for styling embellishments. The difference between the HTML5 site and the XHTML site is minimal, and probably will be barely noticeable to anyone if I can make this work. The content is the same, it is just presented slightly differently.
THE REASON I DID IT THIS WAY
Once the dinosaur browsers are gone, I am hoping I can simply post the HTML5 site, and do away with the old XHTML.
Ultimately, I feel pretty strongly that this is how I want to move forward. I read about progressive enhancement versus graceful degradation, but I have decided that I want to give my client a beautiful website using all of the new semantic tags and simple style selectors to increase SEO and guarantee that when HTML4 goes away, this new site will stand the test of time...at least for a little while.
If you strongly object to this method, I am willing to listen to what you have to say. Please share your thoughts either way.