The state of HTML validation
amazon, Baidu, Document Type Declaration, eBay, Facebook, Google Germany, Google India, Google Japan, Google UK, Groupon, HTML, HTML 4.0, HTML 5, HTML5, LinkedIn, Markup languages, Microsoft, Microsoft Windows, Sina.com., Twitter, United States, UTF-8, validation, XHTML, Yahoo, Yahoo Japan, YouTube, Zynga
What is the state of HTML5 compliance among large sites?