A newer option that I enjoy using is Mojolicious. I don't believe there are any books on it yet, but a fair amount of online documentation. A simple example web service from the Mojolicious web site looks like this:

  # RESTful web service with JSON and text representation
  get '/list/:offset' => sub {
    my $self    = shift;
    my $numbers = [0 .. $self->param('offset')];
    $self->respond_to(
      json => {json => $numbers},
      txt  => {text => join(',', @$numbers)}
    );
  };
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