use Tk;

$top = new MainWindow;
$t = $top->ROText->pack;
$t->tagConfigure('blue_text', -foreground => 'blue');
for (@INC) {
    $t->insert("end", "<$_>\n");
}
$t->tagAdd('blue_text', 'end -2 lines', 'end - 1 chars');

MainLoop;