title: Using Firebug, under <DOCTYPE> why is the first line <html class= "bunch of tags inserted here">
body: <p>I wanted to view how other people code their websites, but got stuck trying to understand what this does:</p>
  
  <pre><code>&lt;html class="js flexbox flexboxlegacy canvas canvastext webgl no-touch geolocation postmessage no-websqldatabase indexeddb hashchange
               history draganddrop websockets rgba hsla multiplebgs backgroundsize borderimage borderradius boxshadow textshadow opacity
               cssanimations csscolumns cssgradients no-cssreflections csstransforms csstransforms3d csstransitions fontface generatedcontent
               video audio localstorage sessionstorage webworkers applicationcache svg inlinesvg smil svgclippaths"
        lang="en" style=""&gt;
  </code></pre>
  
  <p>What is the purpose of this and can someone please explain it to me? </p>