title: Why does Firefox display empty elements with closing tags in its web inspector?
body: <p>As HTML5 is not an XML-based language, we can forget the self closing tags. That's great. So when I want to insert a new horizontal line, I just write <code>&lt;hr&gt;</code> and not <code>&lt;hr /&gt;</code>.</p>
  
  <p>But when I inspect the <code>&lt;hr&gt;</code> element in Firefox, it renders as <code>&lt;hr&gt;&lt;/hr&gt;</code>. It does not happen in any other browser.</p>
  
  <p>Why does this happen? Is this some compatibility issue with Firefox?</p>