One of the best reasons for you to embrace HTML5 today is that it works in most existing browsers. Right now, even in Internet Explorer 6, you can start using HTML5 and slowly transition your markup. It’ll even validate with the W3C’s validation service (conditionally, of course, because the standards are still evolving).
If you’ve worked with HTML or XML, you’ve come across the doctype declaration before. It’s used to tell validators and editors what tags and attributes you can use and how the document should be formed. It’s
also used by a lot of web browsers to determine how the browser will render the page. A valid doctype often causes browsers to render pages in “standards mode.”
Compared to the rather verbose XHTML 1.0 Transitional doctype used by many sites:
the HTML5 doctype is ridiculously simple:
<!DOCTYPE html PUBLIC “-//W3C//DTD XHTML 1.0 Transitional//EN”
Place that at the top of the document, and you’re using HTML5.
Down! oad html5_why/index.html
Of course, you can’t use any of the new HTML5 elements that your target browsers don’t yet support, but your document will validate as HTML5.