digraph {
  concentrate = true;
  nodesep = 1.3;

  CUPS[fontname=Monospace,shape=box];

  socket_bridge[label="upstart-socket-bridge",fontname=Monospace,shape=box,];
  ippusb_manager[fontname=Monospace,shape=box];
  ippusbxd[fontname=Monospace,shape=box];

  Printer[shape=box];

  cups_and_manager[label="Unix socket"];
  cups_and_xd[label="Unix socket"];
  xd_and_printer[label="USB connection"];

  // Links CUPS to the sockets for ippusb_manager and for ippusbxd.
  CUPS->cups_and_manager[weight=1000];
  cups_and_manager->CUPS[weight=1000];
  CUPS->cups_and_xd[weight=1000];
  cups_and_xd->CUPS[weight=1000];

  // Links the socket, upstart-socket-bridge, and ippusb_manager together.
  cups_and_manager->socket_bridge[label="is mediated by"];
  cups_and_manager->ippusb_manager;
  socket_bridge->ippusb_manager[label="starts"];
  ippusb_manager->cups_and_manager;

  // Links the socket, ippusbxd, and ippusb_manager together.
  ippusbxd->cups_and_xd;
  cups_and_xd->ippusbxd;
  ippusb_manager->ippusbxd[label="starts or keeps alive"];

  // Links ippusbxd to the printer.
  ippusbxd->xd_and_printer;
  xd_and_printer->ippusbxd;
  Printer->xd_and_printer;
  xd_and_printer->Printer;

  // Aligns the Unix sockets.
  {rank=same; cups_and_manager cups_and_xd}

  // Aligns ippusb_manager and ippusbxd.
  {rank=same; ippusb_manager ippusbxd}
}