So far, we have learned about how URL redirector programs communicate with Squid and how we can write our own URL redirector programs. Now, let's have a look at a few popular URL redirectors. For a full list of available redirector programs, please visit http://www.squid-cache.org/Misc/related-software.html.
SquidGuard is a combination of filter, URL rewriter, and an access control plugin for Squid. The main features of SquidGuard includes the fact that it is fast, free, flexible, and ease of installation. Below are a few use cases of SquidGuard:
Limiting access for some users to a list of well known web servers or URLs
Blocking access for some users based on blacklists
Redirect blocked URLs to pages containing helpful information
Redirect unregistered users to registration pages
And much more...
For more details on SquidGuard, please see http://www.squidguard.org/.