This is an example of an interactive HTML form using Perl

#!/usr/bin/perl

 # script: customizable.pl

 use CGI qw/:standard/;

 $color = param('color') || 'white';

 print header,

     start_html({-bgcolor=>$color},'Customizable Page'),

     h1('Customizable Page'),

     "Set this page's background color to:",br,

     start_form,

     radio_group(-name=>'color',

                    -value=>['white','red','green','black',

                             'blue','silver','cyan'],

                    -cols=>2),

     submit(-name=>'Set Background'),

     end_form,

     p,

     hr,

     end_html;