ffproxy is a filtering HTTP/HTTPS proxy server. It is able to filter by 
host, URL, and header.  Custom header entries can be filtered and 
added. It can even drop its privileges and optionally chroot() to some 
directory. Logging to syslog() is supported, as is using another 
auxiliary proxy server. An HTTP accelerator feature (acting as a 
front-end to an HTTP server) is included.  Contacting IPv6 servers as 
well as binding to IPv6 is supported and allows transparent IPv6 over 
IPv4 browsing (and vice versa).
