title: Java graph library for visualizing dynamic and hierarchical graphs
body: <p>For my Master’s project, I have to provide a graph visualization functionality in my lab (The lab currently has no way to visualize graph based data). Following are the requirements that my advisor has (till now) listed :</p>
  
  <ol>
  <li>The lab uses Java.</li>
  <li>The graph contains about 200 million nodes.</li>
  <li>Hierarchical graph visualization functionality is desired. (i.e. a graph in which a node is another graph. When such a node is clicked, the underlying graph should be displayed/magnified).</li>
  <li>Dynamic graphs should be modeled i.e. the underlying graph will change with time. This change should be reflected in the visualization.</li>
  <li>Should be easier to use/master (I would be the only person working on this.)</li>
  <li>Open-source/Freeware desired. However my adviser says they would be willing to pay if such a software is not available in the open-source market.</li>
  </ol>
  
  <p>I would be writing code to interface the graph visualisation tool with the existing lab framework. I’ve been asked to search for and make use of an existing graph visualisation tool. </p>
  
  <p>Appreciate if anyone can help me with this!</p>