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80 >1. General Information</A
88 >1.1. Who should give <SPAN
94 > Anyone who is interested in security, privacy, or in
95 finer-grained control over their web and Internet experience.
104 >1.2. Is Privoxy the best choice for
111 > is certainly a good choice, especially for those who want more
112 control and security. Those with the willingness to read the documentation
113 and the ability to fine-tune their installation will benefit the most.
120 strengths is that it is highly configurable giving you the ability to
121 completely personalize your installation. Being familiar with, or at least
122 having an interest in learning about <A
123 HREF="http://en.wikipedia.org/wiki/Http"
126 > and other networking
128 HREF="http://en.wikipedia.org/wiki/Html"
133 HREF="http://en.wikipedia.org/wiki/Regular_expressions"
141 will be a big plus and will help you get the most out of <SPAN
145 A new installation just includes a very basic configuration. The user
146 should take this as a starting point only, and enhance it as he or she
147 sees fit. In fact, the user is encouraged, and expected to, fine-tune the
154 > configuration can be done
156 HREF="http://en.wikipedia.org/wiki/Web_browser"
160 But there are areas where configuration is done using a
162 HREF="http://en.wikipedia.org/wiki/Text_editors"
166 to edit configuration files. Also note that the web-based action editor
167 doesn't use authentication and should only be enabled in environments
168 where all clients with access to <SPAN
171 > listening port can be trusted.
180 >1.3. What is a <SPAN
188 HREF="http://en.wikipedia.org/wiki/Proxy_server"
192 is a service, based on a software such as
196 >, that clients (i.e. browsers) can use
197 instead of connecting directly to web servers on the Internet. The
198 clients then ask the proxy to fetch the objects they need (web pages,
199 images, movies etc) on their behalf, and when the proxy has done so, it
200 hands the results back to the client. It is a <SPAN
205 HREF="http://en.wikipedia.org/wiki/Proxy_server"
212 > There are many reasons to use web proxies, such as security (firewalling),
213 efficiency (caching) and others, and there are any number of proxies
214 to accommodate those needs.
220 > is a proxy that is primarily focused on privacy
221 protection, ad and junk elimination and freeing the user from restrictions placed on his
222 activities. Sitting between your browser(s) and the Internet,
223 it is in a perfect position to filter outbound personal information that your
224 browser is leaking, as well as inbound junk. It uses a variety of techniques to do
225 this, all of which are under your complete control via the various configuration
226 files and options. Being a proxy also makes it easier to share
227 configurations among multiple browsers and/or users.
236 >1.4. Does Privoxy do anything more than ad blocking?</A
240 Yes, ad blocking is but one possible use. There are many, many ways <SPAN
244 can be used to sanitize and customize web browsing. </P
252 >1.5. What is this new version of
259 > A long time ago, there was the
261 HREF="http://www.junkbusters.com/ijb.html"
265 >Internet Junkbuster</SPAN
268 by Anonymous Coders and <A
269 HREF="http://www.junkbusters.com/"
273 >. This saved many users a lot of pain in the early days of
274 web advertising and user tracking.</P
276 > But the web, its protocols and standards, and with it, the techniques for
277 forcing ads on users, give up autonomy over their browsing, and
278 for tracking them, keeps evolving. Unfortunately, the <SPAN
282 > did not. Version 2.0.2, published in 1998, was
283 (and is) the last official
285 HREF="http://www.junkbusters.com/ijbdist.html#release"
290 HREF="http://www.junkbusters.com"
292 >Junkbusters Corporation</A
294 Fortunately, it had been released under the GNU
296 HREF="http://www.gnu.org/licenses/gpl.html"
299 >, which allowed further
300 development by others.</P
302 > So Stefan Waldherr started maintaining an
304 HREF="http://www.waldherr.org/junkbuster/"
306 >improved version of the
308 >, to which eventually a number of people contributed patches.
309 It could already replace banners with a transparent image, and had a first
310 version of pop-up killing, but it was still very closely based on the
311 original, with all its limitations, such as the lack of HTTP/1.1 support,
312 flexible per-site configuration, or content modification. The last release
313 from this effort was version 2.0.2-10, published in 2000.</P
317 HREF="http://www.privoxy.org/user-manual/copyright.html#AUTHORS"
321 picked up the thread, and started turning the software inside out, upside down,
322 and then reassembled it, adding many
324 HREF="http://www.privoxy.org/user-manual/introduction.html#FEATURES"
330 > The result of this is <SPAN
334 stable version, 3.0, was released August, 2002.
346 >? Why change the name from
347 Junkbuster at all?</A
350 > Though outdated, <A
351 HREF="http://junkbusters.com/"
353 >Junkbusters Corporation</A
355 continues to offer their original version of the <SPAN
363 >-derived software under the same name
366 > There are also potential legal complications from our use of the
370 > name, which is a registered trademark of
372 HREF="http://junkbusters.com/"
374 >Junkbusters Corporation</A
376 There are, however, no objections from Junkbusters Corporation to the
380 > project itself, and they, in fact, still
381 share our ideals and goals.</P
383 > The developers also believed that there are so many improvements over the original
384 code, that it was time to make a clean break from the past and make
385 a name in their own right.</P
397 >Privacy Enhancing Proxy</I
401 modification and junk suppression gives <SPAN
408 control, more freedom, and allows you to browse your personal and
426 >1.7. How does Privoxy differ
427 from the old Junkbuster?</A
437 > left off. All the old features remain.
441 > still blocks ads and banners,
443 HREF="http://en.wikipedia.org/wiki/Browser_cookie"
447 helps protect your privacy. But, most of these features have been enhanced,
448 and many new ones have been added, all in the same vein.
454 >'s new features include:</P
461 > Can be run as an "intercepting" proxy, which obviates the need to
462 configure browsers individually.
467 > Sophisticated actions and filters for manipulating both server and client
473 > Can be chained with other proxies.
478 > Integrated browser based configuration and control utility at <A
479 HREF="http://config.privoxy.org/"
481 >http://config.privoxy.org/</A
488 tracing of rule and filter effects. Remote toggling.
493 > Web page filtering (text replacements, removes banners based on size,
497 >, JavaScript and HTML annoyances,
498 pop-up windows, etc.)
503 > Modularized configuration that allows for standard settings and
504 user settings to reside in separate files, so that installing updated
505 actions files won't overwrite individual user settings.
510 > Support for Perl Compatible Regular Expressions in the configuration files, and
511 a more sophisticated and flexible configuration syntax.
516 > Improved cookie management features (e.g. session based cookies).
526 > Bypass many click-tracking scripts (avoids script redirection).
531 > Multi-threaded (POSIX and native threads).
536 > User-customizable HTML templates for all proxy-generated pages (e.g. "blocked" page).
541 > Auto-detection and re-reading of config file changes.
546 > Improved signal handling, and a true daemon mode (Unix).
551 > Every feature now controllable on a per-site or per-location basis, configuration
552 more powerful and versatile over-all.
557 > Many smaller new features added, limitations and bugs removed.
569 >1.8. How does Privoxy know what is
570 an ad, and what is not?</A
576 >'s approach to blocking ads is twofold:</P
578 > First, there are certain patterns in the <SPAN
585 of banner images. This applies to both the path (you wouldn't guess how many
586 web sites serve their banners from a directory called <SPAN
590 and the host (blocking the big banner hosting services like doublecklick.net
591 already helps a lot). <SPAN
594 > takes advantage of this
596 HREF="../user-manual/actions-file.html#AF-PATTERNS"
600 > to sort out and block the requests for things that sound
601 like they would be ads or banners.</P
603 > Second, banners tend to come in certain <SPAN
610 can't tell the size of an image by its URL without downloading it, and if you
611 do, it's too late to save bandwidth. Therefore, <SPAN
615 also inspects the HTML sources of web pages while they are loaded, and replaces
616 references to images with standard banner sizes by dummy references, so that
617 your browser doesn't request them anymore in the first place.</P
619 > Both of this involves a certain amount of guesswork and is, of course, freely
620 and readily configurable.</P
628 >1.9. Can Privoxy make mistakes?
629 This does not sound very scientific.</A
632 > Actually, it's a black art ;-) And yes, it is always possible to have a broad
633 rule accidentally block or change something by mistake. You will almost surely
634 run into such situations at some point. It is tricky writing rules to
635 cover every conceivable possibility, and not occasionally get false positives.</P
637 > But this should not be a big concern since the
641 > configuration is very flexible, and
642 includes tools to help identify these types of situations so they can be
643 addressed as needed, allowing you to customize your installation.
645 HREF="trouble.html#BADSITE"
646 >See the Troubleshooting section below</A
655 >1.10. Will I have to configure Privoxy
656 before I can use it?</A
659 > That depends on your expectations.
660 The default installation should give you a good starting
661 point, and block <SPAN
667 > ads and unwanted content,
668 but many of the more advanced features are off by default, and require
669 you to activate them. </P
671 > You do have to set up your browser to use
676 HREF="installation.html#FIRSTSTEP"
677 >Installation section below</A
680 > And you will certainly run into situations where there are false positives,
681 or ads not being blocked that you may not want to see. In these cases, you
682 would certainly benefit by customizing <SPAN
686 configuration to more closely match your individual situation. And we
687 encourage you to do this. This is where the real power of
699 >1.11. Can Privoxy run as a server on a network?</A
706 > runs as a server already, and can easily be configured to
710 > more than one client. See <A
711 HREF="configuration.html#LANCONFIG"
712 > How can I set up Privoxy to act as a proxy for my LAN</A
721 >1.12. My browser does the same things as
722 Privoxy. Why should I use Privoxy at all?</A
725 > Modern browsers do indeed have <SPAN
732 functionality as <SPAN
736 adequate for you. But <SPAN
740 versatile and powerful, and can probably do a number of things
741 your browser just can't.
744 > In addition, a proxy is good choice if you use multiple browsers, or
745 have a LAN with multiple computers since <SPAN
748 > can run as a server
749 application. This way all the configuration is in one place, and you don't
750 have to maintain a similar configuration for possibly many browsers or
754 > Note, however, that it's recommended to leverage both your browser's
758 > privacy enhancing features
759 at the same time. While your browser probably lacks some features
763 > offers, it should also be able to do some things more
764 reliable, for example restricting and suppressing JavaScript.
773 >1.13. Why should I trust Privoxy?</A
776 > The most important reason is because you have access to
783 >, and you can control everything. You can
784 check every line of every configuration file yourself. You can check every
785 last bit of source code should you desire. And even if you can't read code,
786 there should be some comfort in knowing that other people can,
787 and do read it. You can build the software from scratch, if you want,
788 so that you know the executable is clean, and that it is
795 >. In fact, we encourage this level of scrutiny. It
796 is one reason we use <SPAN
808 >1.14. Is there is a license or fee? What about a
809 warranty? Registration?</A
815 > is free software and licensed under the <A
816 HREF="http://www.gnu.org/licenses/old-licenses/gpl-2.0.html"
818 >GNU General Public License (GPL) version 2</A
820 It is free to use, copy, modify or distribute as you wish under the terms of this
821 license. Please see the <A
822 HREF="copyright.html"
825 information on the license and copyright. Or the <TT
829 that should be included.
838 > of any kind, expressed, implied or otherwise.
839 That is something that would cost real money ;-) There is no registration either.
848 >1.15. Can Privoxy remove spyware? Adware? Viruses?</A
851 > No, at least not reliably enough to trust it. <SPAN
854 > is not designed to be
855 a malware removal tool and the default configuration doesn't even try to
856 filter out any malware.</P
861 > could help prevent contact from (known) sites that use such
862 tactics with appropriate configuration rules, and thus could conceivably
863 prevent contamination from such sites. However, keeping such a configuration
864 up to date would require a lot of time and effort that would be better spend
865 on keeping your software itself up to date so it doesn't have known
874 >1.16. Can I use Privoxy with other ad-blocking software?</A
880 > should work fine with other proxies and other software in general.</P
882 > But it is probably not necessary to use <SPAN
885 > in conjunction with other
886 ad-blocking products, and this could conceivably cause undesirable results.
887 It might be better to choose one software or the other and work a little to
888 tweak its configuration to your liking.</P
890 > Note that this is an advice specific to ad blocking.</P
898 >1.17. I would like to help you, what can I do?</A
906 >1.17.1. Would you like to participate?</A
915 > need help. There is something for
916 everybody who wants to help us. We welcome new developers, packagers,
917 testers, documentation writers or really anyone with a desire to help in
928 >. There are many other tasks available. In fact,
929 the programmers often can't spend as much time programming because of some
930 of the other, more mundane things that need to be done, like checking the
931 Tracker feedback sections.
935 HREF="https://sourceforge.net/account/register.php"
937 >get an account on SourceForge.net</A
939 and mail your id to the <A
940 HREF="mailto:ijbswa-developers@lists.sourceforge.net"
944 >. Then, please read the <A
945 HREF="../developer-manual/index.html"
947 >Developer's Manual</A
949 the pertinent sections.</P
951 > You can also start helping out without SourceForge.net account,
952 simply by showing up on the mailing list, helping out other users,
953 providing general feedback or reporting problems you noticed.
961 NAME="JOINTEAM-MONEY"
962 >1.17.2. Contribute!</A
965 > We, of course, welcome donations and could use money for domain registering,
966 buying software to test <SPAN
969 > with, and, of course,
970 for regular world-wide get-togethers (hahaha). If you enjoy the software and feel
971 like helping us with a donation, just <A
972 HREF="mailto: ijbswa-developers@lists.sourceforge.net"
976 and get your name on the list of contributors.</P
983 NAME="JOINTEAM-SOFTWARE"
987 > If you are a vendor of a web-related software like a browser, web server
988 or proxy, and would like us to ensure that <SPAN
992 runs smoothly with your product, you might consider supplying us with a
993 copy or license. We can't, however, guarantee that we will fix all potential
994 compatibility issues as a result.</P
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