An example of a Radar chart with an interactive key

The interactive key has been reimplemented as of June 2013 and added to more chart types.

[No canvas support]

This goes in the documents header: 
<script src="RGraph.common.core.js"></script>
<script src="RGraph.common.dynamic.js"></script>
<script src="RGraph.common.key.js"></script>
<script src="RGraph.drawing.rect.js"></script>
<script src="RGraph.radar.js"></script>
Put this where you want the chart to show up: 
<canvas id="cvs" width="450" height="300">
    [No canvas support]
</canvas>
This is the code that generates the chart: