Rebuild HTML docs after adding the sponsor policy
[privoxy.git] / doc / webserver / faq / general.html
index d3e9aad..7acb223 100644 (file)
-<HTML
-><HEAD
-><TITLE
->General Information</TITLE
-><META
-NAME="GENERATOR"
-CONTENT="Modular DocBook HTML Stylesheet Version 1.64
-"><LINK
-REL="HOME"
-TITLE="Privoxy Frequently Asked Questions"
-HREF="index.html"><LINK
-REL="PREVIOUS"
-TITLE="Privoxy Frequently Asked Questions"
-HREF="index.html"><LINK
-REL="NEXT"
-TITLE="Installation"
-HREF="installation.html"><LINK
-REL="STYLESHEET"
-TYPE="text/css"
-HREF="../p_doc.css"></HEAD
-><BODY
-CLASS="SECT1"
-BGCOLOR="#EEEEEE"
-TEXT="#000000"
-LINK="#0000FF"
-VLINK="#840084"
-ALINK="#0000FF"
-><DIV
-CLASS="NAVHEADER"
-><TABLE
-WIDTH="100%"
-BORDER="0"
-CELLPADDING="0"
-CELLSPACING="0"
-><TR
-><TH
-COLSPAN="3"
-ALIGN="center"
->Privoxy Frequently Asked Questions</TH
-></TR
-><TR
-><TD
-WIDTH="10%"
-ALIGN="left"
-VALIGN="bottom"
-><A
-HREF="index.html"
->Prev</A
-></TD
-><TD
-WIDTH="80%"
-ALIGN="center"
-VALIGN="bottom"
-></TD
-><TD
-WIDTH="10%"
-ALIGN="right"
-VALIGN="bottom"
-><A
-HREF="installation.html"
->Next</A
-></TD
-></TR
-></TABLE
-><HR
-ALIGN="LEFT"
-WIDTH="100%"></DIV
-><DIV
-CLASS="SECT1"
-><H1
-CLASS="SECT1"
-><A
-NAME="GENERAL"
->1. General Information</A
-></H1
-><DIV
-CLASS="SECT2"
-><H3
-CLASS="SECT2"
-><A
-NAME="NEWJB"
->1.1. What is this new version of <SPAN
-CLASS="APPLICATION"
->Privoxy</SPAN
->?</A
-></H3
-><P
->  The original <SPAN
-CLASS="APPLICATION"
-><SPAN
-CLASS="TRADEMARK"
->Internet
-  Junkbuster</SPAN
->&trade;</SPAN
-> (tm) is a copyrighted product of <A
-HREF="http://www.junkbusters.com"
-TARGET="_top"
->Junkbusters Corporation</A
->.
-  Development of this effort stopped some time ago as of version 2.0.2. Stefan
-  Waldherr started the ijbswa project on <A
-HREF="http://sourceforge.net/projects/ijbswa/"
-TARGET="_top"
->Sourceforge</A
-> to
-  rekindle development. Other developers subsequently joined with Stefan, and
-  have since added many new features, refinements and enhancements. The result
-  of this effort is <SPAN
-CLASS="APPLICATION"
->Privoxy</SPAN
->.
- </P
-><P
->  <SPAN
-CLASS="APPLICATION"
->Privoxy</SPAN
-> has evolved from the 
-  <SPAN
-CLASS="APPLICATION"
->Junkbuster 2.0.2</SPAN
-> code base, and has advanced
-  significantly at this point. 
- </P
-><P
-> 
-  Please see the <A
-HREF="copyright.html"
->History section</A
-> for more
-  information on the history of <SPAN
-CLASS="APPLICATION"
->Junkbuster</SPAN
-> and 
-  <SPAN
-CLASS="APPLICATION"
->Privoxy</SPAN
->.
- </P
-></DIV
-><DIV
-CLASS="SECT2"
-><H3
-CLASS="SECT2"
-><A
-NAME="AEN39"
->1.2. Why <SPAN
-CLASS="QUOTE"
->"Privoxy"</SPAN
->? Why a name change at all?</A
-></H3
-><P
-> <SPAN
-CLASS="APPLICATION"
->Privoxy</SPAN
-> is the 
- <SPAN
-CLASS="QUOTE"
->"<I
-CLASS="EMPHASIS"
->Privacy Enhancing Proxy</I
->"</SPAN
->.</P
-><P
-> There are potential legal complications from the continued use of the 
- <SPAN
-CLASS="APPLICATION"
->Junkbuster</SPAN
-> name, which is a registered trademark of 
- <A
-HREF="http://junkbusters.com"
-TARGET="_top"
->Junkbusters Corporation</A
->.
- And thus they <SPAN
-CLASS="QUOTE"
->"own"</SPAN
-> the rights to the name.
- (There are, however, no objections from Junkbusters Corporation to the 
- <SPAN
-CLASS="APPLICATION"
->Privoxy</SPAN
-> project itself, and they, in fact, still
- share our ideals and goals.)</P
-><P
-> The developers also believed that there are so many changes from the original 
- code, that it was time to make a clean break from the past and make 
- a name in their own right, especially now with the pending
- release of version 3.0.</P
-></DIV
-><DIV
-CLASS="SECT2"
-><H3
-CLASS="SECT2"
-><A
-NAME="DIFFERS"
->1.3. How does <SPAN
-CLASS="APPLICATION"
->Privoxy</SPAN
-> differ
-from the old <SPAN
-CLASS="APPLICATION"
->Junkbuster?</SPAN
-></A
-></H3
-><P
->  <SPAN
-CLASS="APPLICATION"
->Privoxy</SPAN
-> picks up where
-  <SPAN
-CLASS="APPLICATION"
->Junkbuster</SPAN
-> left off. All the old features remain.
-  The new <SPAN
-CLASS="APPLICATION"
->Privoxy</SPAN
-> still blocks ads and banners,
-  still manages cookies, and still helps protect your privacy. But, these are
-  all enhanced, and many new features have been added, all in the same vein.
- </P
-><P
->  The configuration has changed significantly as well. This is something that
-  users will notice right off the bat if you are upgrading from 
-  <SPAN
-CLASS="APPLICATION"
->Junkbuster</SPAN
-> 2.0.x. The <SPAN
-CLASS="QUOTE"
->"blocklist"</SPAN
->
-  file does not exist any more. This is replaced by <SPAN
-CLASS="QUOTE"
->"actions"</SPAN
->
-  files, such as <TT
-CLASS="FILENAME"
->default.actions</TT
->. This is where most of
-  the per site configuration is now.
- </P
-></DIV
-><DIV
-CLASS="SECT2"
-><H3
-CLASS="SECT2"
-><A
-NAME="FEATURES"
->1.4. What are some of the new features?</A
-></H3
-><P
-> <P
-></P
-><UL
-><LI
-><P
->   Integrated browser based configuration and control utility at <A
-HREF="http://config.privoxy.org/"
-TARGET="_top"
->http://config.privoxy.org/</A
->
-   (shortcut: <A
-HREF="http://p.p/"
-TARGET="_top"
->http://p.p/</A
->). Browser-based
-   tracing of rule and filter effects. Remote toggling.
-  </P
-></LI
-><LI
-><P
->   Web page content filtering (removes banners based on size,
-   invisible <SPAN
-CLASS="QUOTE"
->"web-bugs"</SPAN
->, JavaScript and HTML annoyances, pop-up windows, etc.)
-  </P
-></LI
-><LI
-><P
->   Modularized configuration that allows for standard settings and
-   user settings to reside in separate files, so that installing updated
-   actions files won't overwrite idividual user settings.
-  </P
-></LI
-><LI
-><P
->   HTTP/1.1 compliant (but not all optional 1.1 features are supported).
-  </P
-></LI
-><LI
-><P
->   Support for Perl Compatible Regular Expressions in the configuration files, and 
-   generally a more sophisticated and flexible configuration syntax over
-   previous versions.
-  </P
-></LI
-><LI
-><P
->   Improved cookie management features (e.g. session based cookies).
-  </P
-></LI
-><LI
-><P
->   GIF de-animation. 
-  </P
-></LI
-><LI
-><P
->   Bypass many click-tracking scripts (avoids script redirection).
-  </P
-></LI
-><LI
-><P
->   Multi-threaded (POSIX and native threads).
-  </P
-></LI
-><LI
-><P
->   User-customizable HTML templates for all proxy-generated pages (e.g. "blocked" page).
-  </P
-></LI
-><LI
-><P
->   Auto-detection and re-reading of config file changes.
-  </P
-></LI
-><LI
-><P
->   Improved signal handling, and a true daemon mode (Unix).
-  </P
-></LI
-><LI
-><P
->   Every feature now controllable on a per-site or per-location basis, configuration
-   more powerful and versatile over-all.
-  </P
-></LI
-><LI
-><P
->   Many smaller new features added, limitations and bugs removed, and security holes fixed.
-  </P
-></LI
-></UL
-></P
-></DIV
-><DIV
-CLASS="SECT2"
-><H3
-CLASS="SECT2"
-><A
-NAME="PROXYMORON"
->1.5. What is a <SPAN
-CLASS="QUOTE"
->"proxy"</SPAN
->? How does
-<SPAN
-CLASS="APPLICATION"
->Privoxy</SPAN
-> work?</A
-></H3
-><P
->  When you connect to a web site with <SPAN
-CLASS="APPLICATION"
->Privoxy</SPAN
->, 
-  you are really connecting to your locally running version of 
-  <SPAN
-CLASS="APPLICATION"
->Privoxy</SPAN
->. <SPAN
-CLASS="APPLICATION"
->Privoxy</SPAN
->
-  intercepts your requests for the web page, and relays that to the 
-  <SPAN
-CLASS="QUOTE"
->"real"</SPAN
-> web site. The web site sends the HTTP data stream 
-  back to <SPAN
-CLASS="APPLICATION"
->Privoxy</SPAN
->, where
-  <SPAN
-CLASS="APPLICATION"
->Privoxy</SPAN
-> can work its magic before it 
-  relays this data back to your web browser.
- </P
-><P
->  Since <SPAN
-CLASS="APPLICATION"
->Privoxy</SPAN
-> sits between you and the 
-  WWW, it is in a position to intercept and completely manage all web traffic and 
-  HTTP content before it gets to your browser.
-  <SPAN
-CLASS="APPLICATION"
->Privoxy</SPAN
-> uses various programming methods to do
-  this, all of which is under your control via the various configuration
-  files and options.
- </P
-><P
->  There are many kinds of proxies. <SPAN
-CLASS="APPLICATION"
->Privoxy</SPAN
-> best 
-  fits the <SPAN
-CLASS="QUOTE"
->"filtering proxy"</SPAN
-> category.
- </P
-></DIV
-><DIV
-CLASS="SECT2"
-><H3
-CLASS="SECT2"
-><A
-NAME="AEN117"
->1.6. How does <SPAN
-CLASS="APPLICATION"
->Privoxy</SPAN
-> know what is
-an ad, and what is not?</A
-></H3
-><P
-> <SPAN
-CLASS="APPLICATION"
->Privoxy</SPAN
-> processes all the raw content of every 
- web page. So it reads everything on each page. It then compares this to the
- rules as set up in the configuration files, and looks for any matches to
- these rules. <SPAN
-CLASS="APPLICATION"
->Privoxy</SPAN
-> makes heavy use of
- <SPAN
-CLASS="QUOTE"
->"regular expressions"</SPAN
->. (If you are not familiar with regular
- expressions, it is explained briefly in <A
-HREF="../user-manual/appendix.html"
-TARGET="_top"
->the user manual</A
->.) Regular
- expressions facilitate matching of one text string against another, using
- wildcards to build complex patterns. So <SPAN
-CLASS="APPLICATION"
->Privoxy</SPAN
->
- will typically look for URLs and other content that match certain key words
- and expressions as defined in the configuration files. For instance a URL
- that contains <SPAN
-CLASS="QUOTE"
->"/banners"</SPAN
->, has a high probability of containing
- ad banners, and thus would be a prime candidate to have a matching rule.</P
-><P
-> So <SPAN
-CLASS="APPLICATION"
->Privoxy</SPAN
-> will look for these kinds of obvious 
- looking culprits. And also, will use lists of known organizations that
- specialize in ads. Again, using complex patterns to match as many potential 
- combinations as possible since there tend to be many, many variations used by 
- advertisers, and new ones are being introduced all the time.</P
-></DIV
-><DIV
-CLASS="SECT2"
-><H3
-CLASS="SECT2"
-><A
-NAME="AEN129"
->1.7. Can <SPAN
-CLASS="APPLICATION"
->Privoxy</SPAN
-> make mistakes? 
-This does not sound very scientific.</A
-></H3
-><P
-> Actually, it's a black art ;-) And yes, it is always possible to have a broad rule
- accidentally block something by mistake. There is a good chance you may run 
- into such a situation at some point. It is tricky writing rules to cover
- every conceivable possibility, and not occasionally get false positives.</P
-><P
-> But this should not be a big concern since the
- <SPAN
-CLASS="APPLICATION"
->Privoxy</SPAN
-> configuration is very flexible, and
- includes tools to help identify these types of situations so they can be
- addressed as needed, allowing you to customize your installation.
- (<A
-HREF="trouble.html#AEN576"
->See the Troubleshooting section below</A
->.)</P
-></DIV
-><DIV
-CLASS="SECT2"
-><H3
-CLASS="SECT2"
-><A
-NAME="BROWSERS2"
->1.8. My browser does the same things as
-<SPAN
-CLASS="APPLICATION"
->Privoxy</SPAN
->. Why should I use
-<SPAN
-CLASS="APPLICATION"
->Privoxy</SPAN
-> at all?</A
-></H3
-><P
->  Modern browsers do indeed have <I
-CLASS="EMPHASIS"
->some</I
-> of the same
-  functionality as <SPAN
-CLASS="APPLICATION"
->Privoxy</SPAN
->. Maybe this is
-  adequate for you. But <SPAN
-CLASS="APPLICATION"
->Privoxy</SPAN
-> is much more
-  versatile and powerful, and can do a number of things that browsers just can't.
- </P
-><P
->  In addition, a proxy is good choice if you use multiple browsers, or 
-  have a LAN with multiple computers. This way all the configuration 
-  is in one place, and you don't have to maintain a similar configuration 
-  for possibly many browsers.
+<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01
+Transitional//EN""http://www.w3.org/TR/html4/loose.dtd">
+<html>
+  <head>
+    <title>
+      General Information
+    </title>
+    <meta name="GENERATOR" content=
+    "Modular DocBook HTML Stylesheet Version 1.79">
+    <link rel="HOME" title="Privoxy Frequently Asked Questions" href=
+    "index.html">
+    <link rel="PREVIOUS" title="Privoxy Frequently Asked Questions" href=
+    "index.html">
+    <link rel="NEXT" title="Installation" href="installation.html">
+    <link rel="STYLESHEET" type="text/css" href="../p_doc.css">
+    <meta http-equiv="Content-Type" content="text/html; charset=ISO-8859-1">
+  </head>
+  <body class="SECT1" bgcolor="#EEEEEE" text="#000000" link="#0000FF" vlink=
+  "#840084" alink="#0000FF">
+    <div class="NAVHEADER">
+      <table summary="Header navigation table" width="100%" border="0"
+      cellpadding="0" cellspacing="0">
+        <tr>
+          <th colspan="3" align="center">
+            Privoxy Frequently Asked Questions
+          </th>
+        </tr>
+        <tr>
+          <td width="10%" align="left" valign="bottom">
+            <a href="index.html" accesskey="P">Prev</a>
+          </td>
+          <td width="80%" align="center" valign="bottom">
+          </td>
+          <td width="10%" align="right" valign="bottom">
+            <a href="installation.html" accesskey="N">Next</a>
+          </td>
+        </tr>
+      </table>
+      <hr align="LEFT" width="100%">
+    </div>
+    <div class="SECT1">
+      <h1 class="SECT1">
+        <a name="GENERAL">1. General Information</a>
+      </h1>
+      <div class="SECT2">
+        <h3 class="SECT2">
+          <a name="WHO-USES">1.1. Who should give <span class=
+          "APPLICATION">Privoxy</span> a try?</a>
+        </h3>
+        <p>
+          Anyone who is interested in security, privacy, or in finer-grained
+          control over their web and Internet experience.
+        </p>
+      </div>
+      <div class="SECT2">
+        <h3 class="SECT2">
+          <a name="BESTCHOICE">1.2. Is Privoxy the best choice for me?</a>
+        </h3>
+        <p>
+          <span class="APPLICATION">Privoxy</span> is certainly a good
+          choice, especially for those who want more control and security.
+          Those with the willingness to read the documentation and the
+          ability to fine-tune their installation will benefit the most.
+        </p>
+        <p>
+          One of <span class="APPLICATION">Privoxy's</span> strengths is that
+          it is highly configurable giving you the ability to completely
+          personalize your installation. Being familiar with, or at least
+          having an interest in learning about <a href=
+          "http://en.wikipedia.org/wiki/Http" target="_top">HTTP</a> and
+          other networking protocols, <a href=
+          "http://en.wikipedia.org/wiki/Html" target="_top">HTML</a>, and <a
+          href="http://en.wikipedia.org/wiki/Regular_expressions" target=
+          "_top"><span class="QUOTE">"Regular Expressions"</span></a> will be
+          a big plus and will help you get the most out of <span class=
+          "APPLICATION">Privoxy</span>. A new installation just includes a
+          very basic configuration. The user should take this as a starting
+          point only, and enhance it as he or she sees fit. In fact, the user
+          is encouraged, and expected to, fine-tune the configuration.
+        </p>
+        <p>
+          Much of <span class="APPLICATION">Privoxy's</span> configuration
+          can be done with a <a href=
+          "http://en.wikipedia.org/wiki/Web_browser" target="_top">Web
+          browser</a>. But there are areas where configuration is done using
+          a <a href="http://en.wikipedia.org/wiki/Text_editors" target=
+          "_top">text editor</a> to edit configuration files. Also note that
+          the web-based action editor doesn't use authentication and should
+          only be enabled in environments where all clients with access to
+          <span class="APPLICATION">Privoxy</span> listening port can be
+          trusted.
+        </p>
+      </div>
+      <div class="SECT2">
+        <h3 class="SECT2">
+          <a name="PROXYMORON">1.3. What is a <span class=
+          "QUOTE">"proxy"</span>? How does Privoxy work?</a>
+        </h3>
+        <p>
+          A <a href="http://en.wikipedia.org/wiki/Proxy_server" target=
+          "_top">web proxy</a> is a service, based on a software such as
+          <span class="APPLICATION">Privoxy</span>, that clients (i.e.
+          browsers) can use instead of connecting to web servers directly.
+          The clients then ask the proxy to request objects (web pages,
+          images, movies etc) on their behalf and to forward the data to the
+          clients. It is a <span class="QUOTE">"go-between"</span>. For
+          details, see <a href="http://en.wikipedia.org/wiki/Proxy_server"
+          target="_top">Wikipedia's proxy definition</a>.
+        </p>
+        <p>
+          There are many reasons to use web proxies, such as security
+          (firewalling), efficiency (caching) and others, and there are any
+          number of proxies to accommodate those needs.
+        </p>
+        <p>
+          <span class="APPLICATION">Privoxy</span> is a proxy that is
+          primarily focused on privacy enhancement, ad and junk elimination
+          and freeing the user from restrictions placed on his activities.
+          Sitting between your browser(s) and the Internet, it is in a
+          perfect position to filter outbound personal information that your
+          browser is leaking, as well as inbound junk. It uses a variety of
+          techniques to do this, all of which are under your complete control
+          via the various configuration files and options. Being a proxy also
+          makes it easier to share configurations among multiple browsers
+          and/or users.
+        </p>
+      </div>
+      <div class="SECT2">
+        <h3 class="SECT2">
+          <a name="OTHERSTUFF">1.4. Does Privoxy do anything more than ad
+          blocking?</a>
+        </h3>
+        <p>
+          Yes, ad blocking is but one possible use. There are many, many ways
+          <span class="APPLICATION">Privoxy</span> can be used to sanitize
+          and customize web browsing.
+        </p>
+      </div>
+      <div class="SECT2">
+        <h3 class="SECT2">
+          <a name="NEWJB">1.5. What is this new version of <span class=
+          "QUOTE">"Junkbuster"</span>?</a>
+        </h3>
+        <p>
+          A long time ago, there was the <span class="APPLICATION">Internet
+          Junkbuster</span>, by Anonymous Coders and Junkbusters Corporation.
+          This saved many users a lot of pain in the early days of web
+          advertising and user tracking.
+        </p>
+        <p>
+          But the web, its protocols and standards, and with it, the
+          techniques for forcing ads on users, give up autonomy over their
+          browsing, and for tracking them, keeps evolving. Unfortunately, the
+          <span class="APPLICATION">Internet Junkbuster</span> did not.
+          Version 2.0.2, published in 1998, was the last official release,
+          available from Junkbusters Corporation. Fortunately, it had been
+          released under the GNU <a href=
+          "http://www.gnu.org/licenses/old-licenses/gpl-2.0.html" target=
+          "_top">GPL</a>, which allowed further development by others.
+        </p>
+        <p>
+          So Stefan Waldherr started maintaining an improved version of the
+          software, to which eventually a number of people contributed
+          patches. It could already replace banners with a transparent image,
+          and had a first version of pop-up killing, but it was still very
+          closely based on the original, with all its limitations, such as
+          the lack of HTTP/1.1 support, flexible per-site configuration, or
+          content modification. The last release from this effort was version
+          2.0.2-10, published in 2000.
+        </p>
+        <p>
+          Then, some <a href=
+          "https://www.privoxy.org/user-manual/copyright.html#AUTHORS"
+          target="_top">developers</a> picked up the thread, and started
+          turning the software inside out, upside down, and then reassembled
+          it, adding many <a href=
+          "https://www.privoxy.org/user-manual/introduction.html#FEATURES"
+          target="_top">new features</a> along the way.
+        </p>
+        <p>
+          The result of this is <span class="APPLICATION">Privoxy</span>,
+          whose first stable version, 3.0, was released August, 2002.
+        </p>
+        <p>
+          As of 2012 the Junkbusters Corporation's website
+          (http://www.junkbusters.com/) has been shut down, but Privoxy is
+          still actively maintained.
+        </p>
+      </div>
+      <div class="SECT2">
+        <h3 class="SECT2">
+          <a name="WHYPRIVOXY">1.6. Why <span class="QUOTE">"Privoxy"</span>?
+          Why change the name from Junkbuster at all?</a>
+        </h3>
+        <p>
+          Though outdated, Junkbusters Corporation continued to offer their
+          original version of the <span class="APPLICATION">Internet
+          Junkbuster</span> for a while, so publishing our <span class=
+          "APPLICATION">Junkbuster</span>-derived software under the same
+          name would have led to confusion.
+        </p>
+        <p>
+          There were also potential legal reasons not to use the <span class=
+          "APPLICATION">Junkbuster</span> name, as it was (and maybe still
+          is) a registered trademark of Junkbusters Corporation. There were,
+          however, no objections from Junkbusters Corporation to the <span
+          class="APPLICATION">Privoxy</span> project itself, and they, in
+          fact, shared our ideals and goals.
+        </p>
+        <p>
+          The Privoxy developers also believed that there were so many
+          improvements over the original code, that it was time to make a
+          clean break from the past and make a name in their own right.
+        </p>
+        <p>
+          <span class="APPLICATION">Privoxy</span> is the <span class=
+          "QUOTE">"<span class="emphasis"><i class="EMPHASIS">Privacy
+          Enhancing Proxy</i></span>"</span>. Also, its content modification
+          and junk suppression gives <span class="emphasis"><i class=
+          "EMPHASIS">you</i></span>, the user, more control, more freedom,
+          and allows you to browse your personal and <span class=
+          "QUOTE">"<span class="emphasis"><i class=
+          "EMPHASIS">private</i></span> edition"</span> of the web.
+        </p>
+      </div>
+      <div class="SECT2">
+        <h3 class="SECT2">
+          <a name="DIFFERS">1.7. How does Privoxy differ from the old
+          Junkbuster?</a>
+        </h3>
+        <p>
+          <span class="APPLICATION">Privoxy</span> picks up where <span
+          class="APPLICATION">Junkbuster</span> left off. <span class=
+          "APPLICATION">Privoxy</span> still blocks ads and banners, still
+          manages <a href="http://en.wikipedia.org/wiki/Browser_cookie"
+          target="_top">cookies</a>, and still helps protect your privacy.
+          But, most of these features have been enhanced, and many new ones
+          have been added, all in the same vein.
+        </p>
+        <p>
+          <span class="APPLICATION">Privoxy</span>'s new features include:
+        </p>
+        <p>
+        </p>
+        <ul>
+          <li>
+            <p>
+              Supports "Connection: keep-alive". Outgoing connections can be
+              kept alive independently from the client.
+            </p>
+          </li>
+          <li>
+            <p>
+              Supports IPv6, provided the operating system does so too, and
+              the configure script detects it.
+            </p>
+          </li>
+          <li>
+            <p>
+              Supports tagging which allows to change the behaviour based on
+              client and server headers.
+            </p>
+          </li>
+          <li>
+            <p>
+              Can be run as an "intercepting" proxy, which obviates the need
+              to configure browsers individually.
+            </p>
+          </li>
+          <li>
+            <p>
+              Sophisticated actions and filters for manipulating both server
+              and client headers.
+            </p>
+          </li>
+          <li>
+            <p>
+              Can be chained with other proxies.
+            </p>
+          </li>
+          <li>
+            <p>
+              Integrated browser-based configuration and control utility at
+              <a href="http://config.privoxy.org/" target=
+              "_top">http://config.privoxy.org/</a> (shortcut: <a href=
+              "http://p.p/" target="_top">http://p.p/</a>). Browser-based
+              tracing of rule and filter effects. Remote toggling.
+            </p>
+          </li>
+          <li>
+            <p>
+              Web page filtering (text replacements, removes banners based on
+              size, invisible <span class="QUOTE">"web-bugs"</span> and HTML
+              annoyances, etc.)
+            </p>
+          </li>
+          <li>
+            <p>
+              Modularized configuration that allows for standard settings and
+              user settings to reside in separate files, so that installing
+              updated actions files won't overwrite individual user settings.
+            </p>
+          </li>
+          <li>
+            <p>
+              Support for Perl Compatible Regular Expressions in the
+              configuration files, and a more sophisticated and flexible
+              configuration syntax.
+            </p>
+          </li>
+          <li>
+            <p>
+              GIF de-animation.
+            </p>
+          </li>
+          <li>
+            <p>
+              Bypass many click-tracking scripts (avoids script redirection).
+            </p>
+          </li>
+          <li>
+            <p>
+              User-customizable HTML templates for most proxy-generated pages
+              (e.g. "blocked" page).
+            </p>
+          </li>
+          <li>
+            <p>
+              Auto-detection and re-reading of config file changes.
+            </p>
+          </li>
+          <li>
+            <p>
+              Most features are controllable on a per-site or per-location
+              basis.
+            </p>
+          </li>
+          <li>
+            <p>
+              Many smaller new features added, limitations and bugs removed.
+            </p>
+          </li>
+        </ul>
+      </div>
+      <div class="SECT2">
+        <h3 class="SECT2">
+          <a name="WHATSANAD">1.8. How does Privoxy know what is an ad, and
+          what is not?</a>
+        </h3>
+        <p>
+          <span class="APPLICATION">Privoxy</span>'s approach to blocking ads
+          is twofold:
+        </p>
+        <p>
+          First, there are certain patterns in the <span class="emphasis"><i
+          class="EMPHASIS">locations</i></span> (URLs) of banner images. This
+          applies to both the path (you wouldn't guess how many web sites
+          serve their banners from a directory called <span class=
+          "QUOTE">"banners"</span>!) and the host (blocking the big banner
+          hosting services like doublecklick.net already helps a lot). <span
+          class="APPLICATION">Privoxy</span> takes advantage of this fact by
+          using <a href="../user-manual/actions-file.html#AF-PATTERNS"
+          target="_top">URL patterns</a> to sort out and block the requests
+          for things that sound like they would be ads or banners.
+        </p>
+        <p>
+          Second, banners tend to come in certain <span class="emphasis"><i
+          class="EMPHASIS">sizes</i></span>. But you can't tell the size of
+          an image by its URL without downloading it, and if you do, it's too
+          late to save bandwidth. Therefore, <span class=
+          "APPLICATION">Privoxy</span> also inspects the HTML sources of web
+          pages while they are loaded, and replaces references to images with
+          standard banner sizes by dummy references, so that your browser
+          doesn't request them anymore in the first place.
+        </p>
+        <p>
+          Both of this involves a certain amount of guesswork and is, of
+          course, freely and readily configurable.
+        </p>
+      </div>
+      <div class="SECT2">
+        <h3 class="SECT2">
+          <a name="MISTAKES">1.9. Can Privoxy make mistakes? This does not
+          sound very scientific.</a>
+        </h3>
+        <p>
+          Actually, it's a black art ;-) And yes, it is always possible to
+          have a broad rule accidentally block or change something by
+          mistake. You will almost surely run into such situations at some
+          point. It is tricky writing rules to cover every conceivable
+          possibility, and not occasionally get false positives.
+        </p>
+        <p>
+          But this should not be a big concern since the <span class=
+          "APPLICATION">Privoxy</span> configuration is very flexible, and
+          includes tools to help identify these types of situations so they
+          can be addressed as needed, allowing you to customize your
+          installation. (<a href="trouble.html#BADSITE">See the
+          Troubleshooting section below</a>.)
+        </p>
+      </div>
+      <div class="SECT2">
+        <h3 class="SECT2">
+          <a name="CONFIGORNOT">1.10. Will I have to configure Privoxy before
+          I can use it?</a>
+        </h3>
+        <p>
+          That depends on your expectations. The default installation should
+          give you a good starting point, and block <span class="emphasis"><i
+          class="EMPHASIS">most</i></span> ads and unwanted content, but many
+          of the more advanced features are off by default, and require you
+          to activate them.
+        </p>
+        <p>
+          You do have to set up your browser to use <span class=
+          "APPLICATION">Privoxy</span> (see the <a href=
+          "installation.html#FIRSTSTEP">Installation section below</a>).
+        </p>
+        <p>
+          And you will certainly run into situations where there are false
+          positives, or ads not being blocked that you may not want to see.
+          In these cases, you would certainly benefit by customizing <span
+          class="APPLICATION">Privoxy's</span> configuration to more closely
+          match your individual situation. And we encourage you to do this.
+          This is where the real power of <span class=
+          "APPLICATION">Privoxy</span> lies!
+        </p>
+      </div>
+      <div class="SECT2">
+        <h3 class="SECT2">
+          <a name="LAN">1.11. Can Privoxy run as a server on a network?</a>
+        </h3>
+        <p>
+          Yes, <span class="APPLICATION">Privoxy</span> runs as a server
+          already, and can easily be configured to <span class=
+          "QUOTE">"serve"</span> more than one client. See <a href=
+          "configuration.html#LANCONFIG">How can I set up Privoxy to act as a
+          proxy for my LAN</a> below.
+        </p>
+      </div>
+      <div class="SECT2">
+        <h3 class="SECT2">
+          <a name="BROWSERS2">1.12. My browser does the same things as
+          Privoxy. Why should I use Privoxy at all?</a>
+        </h3>
+        <p>
+          Modern browsers do indeed have <span class="emphasis"><i class=
+          "EMPHASIS">some</i></span> of the same functionality as <span
+          class="APPLICATION">Privoxy</span>. Maybe this is adequate for you.
+          But <span class="APPLICATION">Privoxy</span> is very versatile and
+          powerful, and can probably do a number of things your browser just
+          can't.
+        </p>
+        <p>
+          In addition, a proxy is good choice if you use multiple browsers,
+          or have a LAN with multiple computers since <span class=
+          "APPLICATION">Privoxy</span> can run as a server application. This
+          way all the configuration is in one place, and you don't have to
+          maintain a similar configuration for possibly many browsers or
+          users.
+        </p>
+        <p>
+          Note, however, that it's recommended to leverage both your
+          browser's and <span class="APPLICATION">Privoxy's</span> privacy
+          enhancing features at the same time. While your browser probably
+          lacks some features <span class="APPLICATION">Privoxy</span>
+          offers, it should also be able to do some things more reliably, for
+          example restricting and suppressing JavaScript.
+        </p>
+      </div>
+      <div class="SECT2">
+        <h3 class="SECT2">
+          <a name="WHYTRUST">1.13. Why should I trust Privoxy?</a>
+        </h3>
+        <p>
+          The most important reason is because you have access to <span
+          class="emphasis"><i class="EMPHASIS">everything</i></span>, and you
+          can control everything. You can check every line of every
+          configuration file yourself. You can check every last bit of source
+          code should you desire. And even if you can't read code, there
+          should be some comfort in knowing that other people can, and do
+          read it. You can build the software from scratch, if you want, so
+          that you know the executable is clean, and that it is <span class=
+          "emphasis"><i class="EMPHASIS">yours</i></span>. In fact, we
+          encourage this level of scrutiny. It is one reason we use <span
+          class="APPLICATION">Privoxy</span> ourselves.
+        </p>
+      </div>
+      <div class="SECT2">
+        <h3 class="SECT2">
+          <a name="LICENSE">1.14. Is there is a license or fee? What about a
+          warranty? Registration?</a>
+        </h3>
+        <p>
+          <span class="APPLICATION">Privoxy</span> is free software and
+          licensed under the <a href=
+          "http://www.gnu.org/licenses/old-licenses/gpl-2.0.html" target=
+          "_top">GNU General Public License (GPL) version 2</a>. It is free
+          to use, copy, modify or distribute as you wish under the terms of
+          this license. Please see the <a href="copyright.html">Copyright</a>
+          section for more information on the license and copyright. Or the
+          <tt class="FILENAME">LICENSE</tt> file that should be included.
+        </p>
+        <p>
+          There is <span class="emphasis"><i class="EMPHASIS">no
+          warranty</i></span> of any kind, expressed, implied or otherwise.
+          That is something that would cost real money ;-) There is no
+          registration either.
+        </p>
+      </div>
+      <div class="SECT2">
+        <h3 class="SECT2">
+          <a name="SPYWARE">1.15. Can Privoxy remove spyware? Adware?
+          Viruses?</a>
+        </h3>
+        <p>
+          No, at least not reliably enough to trust it. <span class=
+          "APPLICATION">Privoxy</span> is not designed to be a malware
+          removal tool and the default configuration doesn't even try to
+          filter out any malware.
+        </p>
+        <p>
+          <span class="APPLICATION">Privoxy</span> could help prevent contact
+          from (known) sites that use such tactics with appropriate
+          configuration rules, and thus could conceivably prevent
+          contamination from such sites. However, keeping such a
+          configuration up to date would require a lot of time and effort
+          that would be better spend on keeping your software itself up to
+          date so it doesn't have known vulnerabilities.
+        </p>
+      </div>
+      <div class="SECT2">
+        <h3 class="SECT2">
+          <a name="OTHERADS">1.16. Can I use Privoxy with other ad-blocking
+          software?</a>
+        </h3>
+        <p>
+          <span class="APPLICATION">Privoxy</span> should work fine with
+          other proxies and other software in general.
+        </p>
+        <p>
+          But it is probably not necessary to use <span class=
+          "APPLICATION">Privoxy</span> in conjunction with other ad-blocking
+          products, and this could conceivably cause undesirable results. It
+          might be better to choose one software or the other and work a
+          little to tweak its configuration to your liking.
+        </p>
+        <p>
+          Note that this is an advice specific to ad blocking.
+        </p>
+      </div>
+      <div class="SECT2">
+        <h3 class="SECT2">
+          <a name="HELP-THE-DEVELOPERS">1.17. I would like to help you, what
+          can I do?</a>
+        </h3>
+        <div class="SECT3">
+          <h4 class="SECT3">
+            <a name="PARTICIPATE">1.17.1. Would you like to participate?</a>
+          </h4>
+          <p>
+            Well, we <span class="emphasis"><i class=
+            "EMPHASIS">always</i></span> need help. There is something for
+            everybody who wants to help us. We welcome new developers,
+            packagers, testers, documentation writers or really anyone with a
+            desire to help in any way. You <span class="emphasis"><i class=
+            "EMPHASIS">DO NOT</i></span> need to be a <span class=
+            "QUOTE">"programmer"</span>. There are many other tasks
+            available. In fact, the programmers often can't spend as much
+            time programming because of some of the other, more mundane
+            things that need to be done, like checking the Tracker feedback
+            sections or responding to user questions on the mailing lists.
+          </p>
+          <p>
+            So first thing, subscribe to the <a href=
+            "https://lists.privoxy.org/mailman/listinfo/privoxy-users"
+            target="_top">Privoxy Users</a> or the <a href=
+            "https://lists.privoxy.org/mailman/listinfo/privoxy-devel"
+            target="_top">Privoxy Developers</a> mailing list, join the
+            discussion, help out other users, provide general feedback or
+            report problems you noticed.
+          </p>
+          <p>
+            If you intend to help out with the trackers, you also might want
+            to <a href="https://sourceforge.net/user/registration" target=
+            "_top">get an account on SourceForge.net</a> so we don't confuse
+            you with the other name-less users.
+          </p>
+          <p>
+            We also have a <a href="../developer-manual/index.html" target=
+            "_top">Developer's Manual</a>. While it is partly out of date,
+            it's still worth reading.
+          </p>
+          <p>
+            Our <a href=
+            "http://ijbswa.cvs.sourceforge.net/viewvc/ijbswa/current/TODO?view=markup"
+             target="_top">TODO list</a> may be of interest to you as well.
+            Please let us know if you want to work on one of the items
+            listed.
+          </p>
+        </div>
+        <div class="SECT3">
+          <h4 class="SECT3">
+            <a name="DONATE">1.17.2. Would you like to donate?</a>
+          </h4>
+          <p>
+            Donations are welcome. Our <a href=
+            "http://ijbswa.cvs.sourceforge.net/viewvc/ijbswa/current/TODO?view=markup"
+             target="_top">TODO list</a> is rather long and being able to pay
+            one (or more) developers to work on Privoxy would make a huge
+            difference, even if it was only for a couple of weeks. Donations
+            may also be used for Privoxy-related travel expenses (for example
+            to attend conferences), for hardware used for Privoxy development
+            and for hosting expenses etc.
+          </p>
+          <p>
+            <span class="APPLICATION">Privoxy</span> is an associated project
+            of <a href="http://www.spi-inc.org/" target="_top">Software in
+            the Public Interest (SPI)</a>, which allows us to receive
+            tax-deductible donations in the United States. If you want to
+            donate through SPI, please use <a href=
+            "http://www.spi-inc.org/donations" target="_top">SPI's donation
+            page</a> to see what the options are.
+          </p>
+          <p>
+            You can also donate to Privoxy using a bank account or a "Paypal"
+            address:
+          </p>
+          <p class="LITERALLAYOUT">
+            &nbsp;Name&nbsp;on&nbsp;account:&nbsp;<a href=
+            "https://www.zwiebelfreunde.de/" target="_top">Zwiebelfreunde
+            e.V.</a><br>
+             &nbsp;IBAN:&nbsp;DE95430609671126825604<br>
+             &nbsp;BIC:&nbsp;GENODEM1GLS<br>
+             &nbsp;Bank:&nbsp;GLS&nbsp;Bank
+          </p>
+          <p class="LITERALLAYOUT">
+            &nbsp;"Paypal"&nbsp;address:&nbsp;privoxy@zwiebelfreunde.de
+          </p>
+          <p>
+            Donations made through Zwiebelfreunde e.V. are tax-deductible in
+            Germany and other countries that recognize German charitable
+            clubs. Feel free to use the Subject field to provide a name to be
+            credited and a list of TODO list items you are interested in the
+            most. For example: Max Mustermann: #16, #1, #14.
+          </p>
+          <p>
+            Note that donations made through Zwiebelfreunde e.V. currently
+            can't be checked automatically so you may not get credited right
+            away. The credits currently reflect donations received before
+            2016-01-14.
+          </p>
+          <p>
+            If you have any questions regarding donations please mail to
+            either the public user mailing list or, if it's a private matter,
+            to <a href="mailto:fk@fabiankeil.de" target="_top">Fabian
+            Keil</a> (Privoxy's SPI liaison) directly.
+          </p>
+        </div>
+      </div>
+      <div class="SECT2">
+        <h2 class="SECT2">
+          <a name="SPONSOR">1.18. How can I become a sponsor and get my logo
+          or link on privoxy.org?</a>
+        </h2>
+        <p>
+          We are currently offering the following sponsor levels as an
+          experiment:
+        </p>
+        <div class="VARIABLELIST">
+          <dl>
+            <dt>
+              Gold (10000 EUR/year)
+            </dt>
+            <dd>
+              <p>
+                Logo shown at the bottom of the <a href=
+                "https://www.privoxy.org/" target="_top">Privoxy
+                homepage</a>. Logo, link and self description on the <a href=
+                "https://www.privoxy.org/sponsors/" target="_top">sponsor
+                page</a>.
+              </p>
+            </dd>
+            <dt>
+              Silver (1000 EUR/year)
+            </dt>
+            <dd>
+              <p>
+                Logo shown randomly at the bottom of the <a href=
+                "https://www.privoxy.org/" target="_top">Privoxy
+                homepage</a>. Logo, link and self description on the <a href=
+                "https://www.privoxy.org/sponsors/" target="_top">sponsor
+                page</a>.
+              </p>
+            </dd>
+            <dt>
+              Bronze (500 EUR/year)
+            </dt>
+            <dd>
+              <p>
+                Logo and link on the <a href=
+                "https://www.privoxy.org/sponsors/" target="_top">sponsor
+                page</a>.
+              </p>
+            </dd>
+          </dl>
+        </div>
+        <p>
+          The logo sizes depend on the sponsor level.
+        </p>
+        <p>
+          The details may change over time but changes will only affect new
+          sponsors (or existing sponsors that explicitly agreed to the
+          changes).
+        </p>
+        <p>
+          If you want to become a sponsor, please contact <a href=
+          "mailto:fk@fabiankeil.de" target="_top">Fabian Keil</a>. New
+          sponsors are only accepted if no developer objects.
+        </p>
+      </div>
+    </div>
+    <div class="NAVFOOTER">
+      <hr align="LEFT" width="100%">
+      <table summary="Footer navigation table" width="100%" border="0"
+      cellpadding="0" cellspacing="0">
+        <tr>
+          <td width="33%" align="left" valign="top">
+            <a href="index.html" accesskey="P">Prev</a>
+          </td>
+          <td width="34%" align="center" valign="top">
+            <a href="index.html" accesskey="H">Home</a>
+          </td>
+          <td width="33%" align="right" valign="top">
+            <a href="installation.html" accesskey="N">Next</a>
+          </td>
+        </tr>
+        <tr>
+          <td width="33%" align="left" valign="top">
+            Privoxy Frequently Asked Questions
+          </td>
+          <td width="34%" align="center" valign="top">
+            &nbsp;
+          </td>
+          <td width="33%" align="right" valign="top">
+            Installation
+          </td>
+        </tr>
+      </table>
+    </div>
+  </body>
+</html>
 
- </P
-></DIV
-><DIV
-CLASS="SECT2"
-><H3
-CLASS="SECT2"
-><A
-NAME="LICENSE"
->1.9. Is there is a license or fee? What about a 
-warranty? Registration?</A
-></H3
-><P
->  <SPAN
-CLASS="APPLICATION"
->Privoxy</SPAN
-> is licensed under the GNU General Public
-  License (GPL). It is free to use, copy, modify or distribute as you wish
-  under the terms of this license.  Please see the Copyright section for more
-  information on the license and copyright.
-
-  </P
-><P
->  There is no warranty of any kind, expressed, implied or otherwise. That is
-  something that would cost real money ;-) There is no registration either.
-  <SPAN
-CLASS="APPLICATION"
->Privoxy</SPAN
-> really is <I
-CLASS="EMPHASIS"
->free</I
->
-  in every respect!
-
- </P
-></DIV
-><DIV
-CLASS="SECT2"
-><H3
-CLASS="SECT2"
-><A
-NAME="JOINTEAM"
->1.10. I would like to help you, what do I do?</A
-></H3
-><DIV
-CLASS="SECT3"
-><H4
-CLASS="SECT3"
-><A
-NAME="JOINTEAM-MONEY"
->1.10.1. Money Money Money</A
-></H4
-><P
-> We, of course, welcome donations and use the money for domain registering,
- regular world-wide get-togethers (hahaha). Anyway, we'll soon describe the
- process how to donate money to the team.</P
-></DIV
-><DIV
-CLASS="SECT3"
-><H4
-CLASS="SECT3"
-><A
-NAME="JOINTEAM-WORK"
->1.10.2. You want to work with us?</A
-></H4
-><P
->   Well, helping the team is always a good idea. We welcome new developers,
-   RPM gurus or documentation makers. Simply get an account on sourceforge.net
-   and mail your id to the developer mailing list. Then read the
-   section Quickstart in the <A
-HREF="../developer-manual/quickstart.html"
-TARGET="_top"
->   Developer's Manual</A
->.</P
-><P
-> Once we have added you to the team, you'll have write access to the CVS
- repository, and together we'll find a suitable task for you.</P
-></DIV
-></DIV
-></DIV
-><DIV
-CLASS="NAVFOOTER"
-><HR
-ALIGN="LEFT"
-WIDTH="100%"><TABLE
-WIDTH="100%"
-BORDER="0"
-CELLPADDING="0"
-CELLSPACING="0"
-><TR
-><TD
-WIDTH="33%"
-ALIGN="left"
-VALIGN="top"
-><A
-HREF="index.html"
->Prev</A
-></TD
-><TD
-WIDTH="34%"
-ALIGN="center"
-VALIGN="top"
-><A
-HREF="index.html"
->Home</A
-></TD
-><TD
-WIDTH="33%"
-ALIGN="right"
-VALIGN="top"
-><A
-HREF="installation.html"
->Next</A
-></TD
-></TR
-><TR
-><TD
-WIDTH="33%"
-ALIGN="left"
-VALIGN="top"
->Privoxy Frequently Asked Questions</TD
-><TD
-WIDTH="34%"
-ALIGN="center"
-VALIGN="top"
->&nbsp;</TD
-><TD
-WIDTH="33%"
-ALIGN="right"
-VALIGN="top"
->Installation</TD
-></TR
-></TABLE
-></DIV
-></BODY
-></HTML
->
\ No newline at end of file