demojs_shim.html

<!doctype html>
<html>
  <head>
    <title>DemoJS submission template</title>
    <meta charset="utf-8" />
  </head>
  <body>
    <canvas id="c"></canvas>
    <script>
var a = document.body;
var b = document.getElementsByTagName('canvas')[0];

function getContext(s) {
  try {
    return b.getContext(s); 
  } catch(e) {
    return null;
  }
}

function c() {
  return getContext('2d');
}

function d() {
  return getContext('webgl') || getContext('experimental-webgl') || getContext('webkit-3d') || getContext('moz-webgl');
}

document.body.clientWidth; // fix bug in webkit: http://qfox.nl/weblog/218
    </script>

    <script>
    // insert your entry here

    // RULES (thx to @kuvos for inspiration)
    //  1. Submissions may be up to 1k (1024 bytes). Fill those damn bytes.
    //  2. Submissions must consist of only js.
    //  3. Any and all externals are strictly forbidden.
    //  4. Must work on Mozilla Firefox 4 and Google Chrome 12 (more support appreciated of course :)
    //  5. It should look roughly similar under both browsers.
    //  6. As you might have seen, you get canvas object and context creation for FREE!
    //  7. Your demo must work in this shim, tell us if there are problems with context creation.
    //  8. GO MAD, audio, eval and WebGL allowed!
    </script>
  </body>
</html>