digraph G {
  graph [rankdir=LR nodesep=0.1 size="3,4"]
  node [shape=box height=0.1]
  subgraph cluster_graphviz {
    graph [label=graphviz style=filled fillcolor=lightblue color=black URL="http://www.graphviz.org/"]
    node [URL="http://www.graphviz.org/"]
    {gd gdtclft dot neato twopi dotneato pathplan tclstubs tclhandle "graph" cdt}->libtcldot
  }
  libfreetype [URL="http://www.freetype.org/"]
  libjpeg [URL="http://www.ijg.org/"]
  libpng [URL="http://www.libpng.org/pub/png/"]
  libz [URL="http://www.gzip.org/zlib/"]
  {libfreetype libjpeg libpng libz}->libtcldot
  webdot [style=filled fillcolor=yellow color=black URL="/webdot"]
  tclsh [URL="http://tcl.activestate.com/"]
  httpd [URL="http://httpd.apache.org/"]
  {libtcldot tclsh httpd}->webdot
}