Sample HTML5 file
<!DOCTYPE html>
<html>
<head>
<title>Title of the document</title>
<script>
var text = "I told you so!";
</script>
</head>
<body>
<math xmlns="http://www.w3.org/1998/Math/MathML">
<mrow>
<msup><mi>a</mi><mn>2</mn></msup>
<mo>+</mo>
<msup><mi>b</mi><mn>2</mn></msup>
<mo>=</mo>
<msup><mi>c</mi><mn>2</mn></msup>
</mrow>
</math>
<!>
<svg xmlns="http://www.w3.org/2000/svg" version="1.1" height="190">
<polygon points="100,10 40,180 190,60 10,60 160,180"
style="fill:lime;stroke:purple;stroke-width:5;fill-rule:evenodd;">
</svg>
<script>
document.write("<p>"+text+"</p>");
document.write("<p>"+text+"</p>");
document.write("<p>"+text+"</p>");
</script>
</body>
</html>