When I use your revised edition, Perl throws:

malformed header from script. Bad header=<?xml version="1.0" encoding=
+": vary-test.cgi
[download]

    print "Content-Type: application/xhtml+xml; charset=UTF-8\n\n";
} else {
    print "Content-Type: text/html; charset=UTF-8\n\n";
[download]

I've been meaning to have a look at plackup. I've seen alot of people using it.

Thanks for mentioning it.

--Chris

#!/usr/bin/perl -Tw
use Perl::Always or die;
my $perl_version = (5.12.5);
print $perl_version;