use strict;
use warnings;
use GraphViz;

my $g = GraphViz->new(layout => 'dot',
                      graph  => {bgcolor => '#FFFFAA'},
                      node   => {fontname => 'Helvetica',
                                 fontsize => '14',
                                 shape => 'circle'},
                       edge  => {color => 'gray' } );

print $!,"\n";
$g->add_node('Linux');
$g->add_node('Debian');
$g->add_node('Ubuntu');
$g->add_node('Fedora');

$g->add_edge('Linux' => 'Debian');
$g->add_edge('Linux' => 'Ubuntu');
$g->add_edge('Linux' => 'Fedora');

open (DAT, ">", "gviz0.png") || die "Oops: $!\n";
binmode DAT;
print DAT $g->as_png;
close(DAT);