Xantrax,
<!DOCTYPE HTML>
<html>
<head>
<title>Untitled</title>
<meta charset="utf-8">
<script src="http://d3js.org/d3.v3.min.js" charset="utf-8"></script>
</head>
<body>
<p>D3 tutorial</p>
<script>
d3.select("p").text("Hello World");
</script>
</body>
</html>