$packagehash = {
          ' IBM Tivoli Runtime Security Services Client ' => {
                                                               'Publisher' => 'IBM',
                                                               'Version' => ' 7.1.0.2 ',
                                                               'ProductCode' => ' com.ibm.rtss.client',
                                                               'ProductName' => ' IBM Tivoli Runtime Security Services Client '
                                                             },
          ' IBM Tivoli Runtime Security Services Software Development Kit ' => {
                                                                                 'Publisher' => 'IBM',
                                                                                 'Version' => ' 7.1.0.2 ',
                                                                                 'ProductCode' => ' com.ibm.rtss.sdk',
                                                                                 'ProductName' => ' IBM Tivoli Runtime Security Services Software Development Kit '
                                                                               },
          ' IBM Tivoli Runtime Security Services Server ' => {
                                                               'Publisher' => 'IBM',
                                                               'Version' => ' 7.1.0.2 ',
                                                               'ProductCode' => ' com.ibm.rtss.server',
                                                               'ProductName' => ' IBM Tivoli Runtime Security Services Server '
                                                             }
        };


##</code><code>##

&getxml($packagehash);

##</code><code>##

sub getxml($) {
      my $hashref = shift;
      foreach my $key ( keys %${hashref} ){
          print $key->{'ProductName'}
          print $key->{'ProductCode'}
          print $key->{'Publisher'}
      ...xml logic...
      }