Directory / File tree with blockdiag.

tree.diag

diagram {
   default_fontsize = 13;      // default value is 11
   default_linecolor = "#999"; // default value is black
   node_width = 64;            // default value is 128
   node_height = 20;           // default value is 40
   span_width = 16;            // default value is 64
   span_height = 10;           // default value is 40

   // classes for node.
   class folder [color = "#fc0", linecolor = "#c90"];
   class file;

   // classes for edge.
   class dummy [style = none];
   class tree  [style = dotted];

   dummy1, dummy2, dummy3     [shape = none];
   root, folder1, folder2     [class = "folder"];
   file1, file2, file3, file4 [class = "file"];

   root -- dummy1  [class = dummy];
   root -- folder1 [class = tree];
   root -- file1   [class = tree];
           folder1 -- dummy2  [class = dummy];
           folder1 -- folder2 [class = tree];
                      folder2 -- dummy3 [class = dummy];
                      folder2 -- file4  [class = tree];
           folder1 -- file2 [class = tree];
           folder1 -- file3 [class = tree];
}