Um, how do you run it?

See Plack and multiple domains. Simplest option

$ cat mycatapps.psgi
#!/usr/bin/perl --
use strict; use warnings;
use MyCatalystApp;
use MyOtherCatalystApp;
use MySharona;
use Plack::App::URLMap;
my $app;
{
    my $urlmap = Plack::App::URLMap->new;
    my $catapp = MyCatalystApp->apply_default_middlewares(MyCatalystAp
+p->psgi_app);
    
    $urlmap->map( '/catapp' => $catapp );

    my $sharona = MySharona->apply_default_middlewares(MySharona->psgi
+_app);
    $urlmap->map( '/sharona' => $sharona );

    my $other = MyOtherCatalystApp->apply_default_middlewares(MyOtherC
+atalystApp->psgi_app);
    $urlmap->map( '/other' => $other );


    $app = $urlmap->to_app;;
}
$app;
[download]

http://advent.plackperl.org/2009/12/day-12-maps-multiple-apps-with-mount-and-urlmap.html