digraph G {
  graph [URL="default.html", BGURL="smbluewhite_paper.gif "]
  node [style=filled]

  // edge URLs are not supported by imagemap clients, but they are allowed.
  edge [color=red]
  1 [color=red]
  4 [color=red]
  2 [color=orange]
  3 [color=orange]
  5 [color=orange]
  6 [color=orange]
  7 [color=green]
  8 [color=green]
  1->2
  2->3
  5->3
  4->5
  4->6
  3->7
  3->8
  6->8
}
