FreeBSD::Ports and FreeBSD::Ports::Port are modules for parsing
FreeBSD's Ports INDEX file and selecting ports that match certain
criteria.

For example, you might want to list ports maintained by tom@FreeBSD.org
sorted alphabetically:
  my $ports = tie my %port, 'FreeBSD::Ports', '/usr/ports/INDEX';
  $ports->maintainer('tom@FreeBSD.org');
  $ports->sort('alpha');
  foreach my $p (keys %port) {
      print $p->as_ascii,"\n";
  }

WWW: https://people.freebsd.org/~tom/portpm/