Beware of XHTML

If you're a web developer, you've probably worked a lot with XHTML, the markup language developed in 1999 to implement HTML as an XML format. Most people who use and promote XHTML do so because they think it's the “next version” of HTML, and they may have heard of some benefits here and there. But there is a lot more to it than you may realize, and if you're using it on your website, even if it validates, you are probably using it incorrectly. [Detail]