You can prosecute F*EX behind a reverse proxy, but then you are limited to
the capabilities of this proxy. For example, if you use apache, then you
have a 2 GB upload limitation and a throughput penality.

Example for apache reverse proxy:

On http://tandem-fahren.de:80  there is an apache
On http://tandem-fahren.de:488 there is a F*EX server
tandem-fahren.de has ip address 78.46.33.142

If you want to contact the F*EX server via alias URL
http://tandem-fahren.de/fex/ then you have to put in httpd.conf:

        Redirect      /fex /fex/
        ProxyRequests Off
        ProxyPass     /fex/ http://tandem-fahren.de:488/
        <Location /fex/>
          ProxyPassReverse   http://tandem-fahren.de:488/
          SetOutputFilter    proxy-html
          ProxyHTMLExtended  On
          ProxyHTMLURLMap    http://tandem-fahren.de:488/ /fex/
          ProxyHTMLURLMap    / /fex/
          ProxyHTMLURLMap    /fex/fex/fex/ /fex/
        </Location>

And write to lib/fex.ph :
	$hostname = 'tandem-fahren.de';
        $reverse_proxy_ip = '78.46.33.142';
        $durl = 'http://tandem-fahren.de/fex/fop';


See also: http://8d.no/fexproxy.html