Install Feedvalidator with Ubuntu 14.04 LTS, lighttpd and CGI.

feedvalidator.md

apt update
apt install git python python-iconvcodec lighttpd
cd /var/www
git clone https://github.com/rubys/feedvalidator.git
chown -R www-data:www-data /var/www/feedvalidator/
service lighttpd start
lighty-enable-mod cgi

Edit /etc/lighttpd/conf-enabled/10-cgi.conf...

...
$HTTP["url"] =~ "^/feedvalidator/" {
  cgi.assign = ( ".cgi" => "/usr/bin/python" )
}
...

Edit /etc/lighttpd/lighttpd.conf...

...
index-file.names            = ( "check.cgi", "index.php", "index.html", "index.lighttpd.html" )
...
static-file.exclude-extensions = ( ".cgi", ".php", ".pl", ".fcgi" )
...

service lighttpd force-reload