All installed on-line documentation will be served via a local HTTP
 server at http://localhost/dwww/. This package runs cron scripts to
 convert available resources to the HTML pages. Executing the dwww
 command starts a sensible WWW browser locally to access them.
 .
 You need to install a CGI-capable HTTP server and enable its CGI script
 capability manually (CGI may be disabled by default for the security
 consideration). For apache2, do something along the following:
 .
  $ sudo a2enmod cgid
  $ sudo systemctl restart apache2
 .
 The default for the HTTP/CGI access is limited to the local user for
 the security consideration.