Privoxy is a web proxy with advanced filtering capabilities for protecting
privacy, filtering web page content, managing cookies, controlling access,
and removing ads, banners, pop-ups and other obnoxious Internet junk.
Privoxy has a very flexible configuration and can be customized to suit
individual needs and tastes. Privoxy has application for both stand-alone
systems and multi-user networks.

Homepage:
http://www.privoxy.org/
