digraph stack
{
  compound=true;
  rankdir="LR";
  node [
    shape="box";
  ]

  subgraph cluster_2 {
	  label="Kernel";
	  event0 [label="/dev/input/event0"]
	  event1 [label="/dev/input/event1"]
  }

  subgraph cluster_0 {
	  label="Compositor process";
	  libinput;
  }

  client [label="Wayland client"];

  event0 -> libinput;
  event1 -> libinput;
  libinput -> client [ltail=cluster_0 label="Wayland protocol"];
}