This is a visualization of which Org-mode files require which other
Org-mode files.  It may not hold any new insights, but I found it
interesting.

    # shell-script
    (echo "digraph {";
      for file in lisp/*.el;do
        name=$(basename $file .el)
        echo "\"$name\";"
        cat $file|sed -n "s/^.*(require '\([^) ]\+\)).*$/\"\1\" -> \"$name\"/p;"
      done;echo "}";
    )|dot -Tsvg > /tmp/org-requires.svg