use Data::Dumper;

my %data;
my @projects= qw ( dogs cats birds horses );
my $langs= { it => 'Italian',
             es => 'Spanish',
             en => 'English' };
my @targets=  qw ( images data links other );
foreach my $project (@projects) {
  foreach my $lang_abbrev (keys %$langs) {
    foreach my $target (@targets) {
      $data{$project}{$lang_abbrev}{$target}=
        $lang_abbrev.$project.'/'.$target.'.tar.bz2';
    }
  }
}

print Dumper(\%data);