The HTML 5 Boilerplate is a an excellent start to a valid HTML5 document, however it isn’t 100%, the HTML 5 Validator reports an error on the X-UA-Compatible attribute;
Bad value X-UA-Compatible for attribute http-equiv on element meta.
[codesyntax lang=”html4strict”]
<meta http-equiv=’X-UA-Compatible’ content=’IE=edge,chrome=1′>
If you’re looking to make it technically valid without affecting functionality, you should be able to just wrap it in a “if IE” tag.
<!–[if IE]><meta http-equiv=’X-UA-Compatible’ content=’IE=edge,chrome=1′><![endif]–>