With the impending completion of the HTML5 spec, I thought I’d summarize the major differences between XHTML and HTML5 that affect me the most in my daily blogging and web development. Figured this might be useful to others.
Void elements (those that cannot contain text or other elements, and thus don’t require an end tag) don’t need to be closed with a nitpicky trailing slash (see: There are only 10 legal XHTML empty tags for more)
<br> is ok! <img src="image.jpg" alt="image"> is ok!
Unquoted attribute-values are ok (if the value doesn’t contain spaces)
<input type=checkbox> is ok!
Empty attributes (those that don’t require a value) don’t need values
<input type=checkbox checked> is ok!
The acronym element is now obsolete, use abbr instead (which is conveniently 3 characters shorter)
<abbr title="hypertext markup language">HTML</abbr>