8e6 Technologies
   Maker of stand-alone external Internet content filtering appliances. [Windows]
   http://www.8e6.com/

Application-Specific Proxy Servers as HTTP Stream Transducers
   Paper from W3C discussing research on an application specific Web proxy.
   http://www.w3.org/Conferences/WWW4/Papers/56/

Configuring Your Mac to Work With Filter Proxy Settings
   Instructions and links to relevant tools.
   http://macfilter.freeyellow.com/

FilterProxy
   An HTML-rewriting proxy with Web-forms based configuration and modules for XSLT, GIF deanimation, and compression. [Perl]
   http://filterproxy.sourceforge.net/

Internet Data Filtering Talk
   Presentation by Christopher Browne to the North Texas Linux Users Group (NTLUG) in October 1997.
   http://cbbrowne.com/info/ifilter.html

Internet Filter
   Protect Your Network With Untangle's Free Internet Filter Software. This Web Filter Protects From Viruses, Spyware, Hackers, Identity Thieves & More!
   http://www.untangle.com/

LANguard
   Keyword-based content filtering and virus scanning for Microsoft ISA Server.
   http://www.gfi.com/dsec/

Muffin
   Open-source cross-platform filtering Web proxy server written in Java. It has a public API to create additional filters.
   http://muffin.doit.org/

Mutating Web proxy (RabbIT)
   A Java application which will cache, compress images and remove unwanted content in order to speed up the browsing process.
   http://rabbit-proxy.sourceforge.net/

Norton Internet Security
   Commercial software for Windows 98/Me/2000/XP. Mainly used as a firewall and anti-virus checker, but has ad blocking and parental control capabilities.
   http://www.symantec.com/home_homeoffice/products/category.jsp?pcid=is

Privoxy
   A web proxy with advanced filtering capabilities for protecting privacy, modifying web page content, managing cookies, controlling access, and removing ads, banners, pop-ups and other Internet junk. Based on Internet Junkbuster.
   http://www.privoxy.org/

Proxomitron, The
   General proxy with text-matching rules for transforming and filtering pages and HTTP headers. Includes filters for animated GIFs, pop-up windows, ad banners, and dynamic HTML.
   http://www.proxomitron.info/

PureSight
   PureSight is a password protected, easy to use program, that runs silently on the computer and controls all of the communication to and from the PC.
   http://www.puresight.net/

SquidGuard
   A combined filter, redirector and access controller plugin for Squid.
   http://www.squidguard.org/

Using a Hosts File To Make The Internet Not Suck (as much)
   Basic introduction to hosts file usage.
   http://someonewhocares.org/hosts/

WebFilter
   Extension to Cern's httpd web server to filter out annoying parts of web pages.
   http://www-math.uni-paderborn.de/~axel/NoShit/

WebSense
   Internet access management system allows an organization to monitor, report and manage internal Internet use.
   http://www.websense.com/

X-Stop Internet Access Management Solutions
   X-Stop allows homes and schools to provide safe Internet access and corporations to manage their employee's Internet usage. It facilitates an organization's goal of maintaining employee and network productivity while reducing the risk of legal liability.
   http://www.xstop.com