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];
  ippusb_bridge[fontname=Monospace,shape=box];

  Printer[shape=box];

  cups_and_manager[label="Unix socket"];
  cups_and_bridge[label="Unix socket"];
  bridge_and_printer[label="USB connection"];

  // Links CUPS to the sockets for ippusb_manager and for ippusb_bridge.
  CUPS->cups_and_manager[weight=1000];
  cups_and_manager->CUPS[weight=1000];
  CUPS->cups_and_bridge[weight=1000];
  cups_and_bridge->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, ippusb_bridge, and ippusb_manager together.
  ippusb_bridge->cups_and_bridge;
  cups_and_bridge->ippusb_bridge;
  ippusb_manager->ippusb_bridge[label="starts or keeps alive"];

  // Links ippusb_bridge to the printer.
  ippusb_bridge->bridge_and_printer;
  bridge_and_printer->ippusb_bridge;
  Printer->bridge_and_printer;
  bridge_and_printer->Printer;

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

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