D3 and Custom Data Attributes by mbostock

index.html

<!DOCTYPE html>
<meta charset="utf-8">
<ul id="list">
  <li data-username="shawnbot">Shawn Allen</li>
  <li data-username="mbostock">Mike Bostock</li>
</ul>
<script src="//d3js.org/d3.v3.min.js"></script>
<script>

d3.selectAll("#list li")
    .datum(function() { return this.dataset; })
    .sort(function(a, b) { return d3.ascending(a.username, b.username); });

</script>