This example belongs to the presentation made to the OSGeo local group in Barcelona Geoinquiets The example is an adaptation from Mike Bostock’s Symbol Map example
<!DOCTYPE html>
<meta charset="utf-8">
<style>
.states {
  fill: #ccc;
  stroke: #fff;
}
</style>
<body>
<script src="http://d3js.org/d3.v3.min.js"></script>
<script src="http://d3js.org/topojson.v0.min.js"></script>
<script>
var width = 960,
    height = 500;
var path = d3.geo.path();
var svg = d3.select("body").append("svg")
    .attr("width", width)
    .attr("height", height);
d3.json("/mbostock/raw/4090846/us.json", function(error, us) {
  svg.append("path")
      .attr("class", "states")
      .datum(topojson.object(us, us.objects.states))
      .attr("d", path);
  
});
</script>