use strict;
use warnings; 
use GRID::Cluster;

my $script = "script.plx";

my @processes = (...);
my @machines = (...);
my %max_num_processes = (...);

my $cluster = GRID::Cluster->new(
  	host_names => \@machines, max_num_np => \%max_num_processes,
);

$cluster->qx(@processes);