#!/usr/bin/perl -w
use strict;
use XML::Simple;

my $parser = new XML::Simple(ForceArray => ['process']);
my $ref = $parser->XMLin('c:\temp\file.xml');
foreach my $host (keys(%$ref)){
  foreach my $proc (keys(%{$ref->{$host}->{process}})){
    print "$proc is running on $host\n";
  }
}

##</code><code>##

#!/usr/bin/perl -w
use strict;
use XML::Simple;

my $parser = new XML::Simple(ForceArray => ['process']);
my $ref = $parser->XMLin('c:\temp\file.xml');
while (my ($host, $processes) = each %$ref){
  foreach my $proc (keys(%{$processes->{process}})){
    print "$proc is running on $host\n";
  }
}

##</code><code>##

use XML::Rules;
my $parser = XML::Rules->new(
	rules => {
		process => sub { '@list' => $_[1]->{name}},
		_default => sub { $_[0] => $_[1]->{list}},
		config => 'pass no content',
	}
);
my $data = $parser->parse(\*DATA);
#use Data::Dumper;
#print Dumper($data);

foreach my $host (sort keys %$data) {
	foreach my $proc (@{$data->{$host}}) {
		print "$host runs $proc\n";
	}
}

__DATA__
<?xml version="1.0" encoding="utf-8"?>
<config>
...