title: How to make an interactive tree chart with d3?
body: <p>Is there any sample of how one could design an interactive tree chart like in the pearltrees.com web site (see <a href="http://www.pearltrees.com/#/N-s=1_465472&amp;N-p=6845530&amp;N-u=1_37150&amp;N-fa=465472&amp;N-f=1_465472" rel="noreferrer">here</a> for example) with D3 ?</p>
  
  <p>thanks for any help !</p>