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43 <a name="GENERAL">1. General Information</a>
47 <a name="WHO-USES">1.1. Who should give <span class=
48 "APPLICATION">Privoxy</span> a try?</a>
51 Anyone who is interested in security, privacy, or in finer-grained
52 control over their web and Internet experience.
57 <a name="BESTCHOICE">1.2. Is Privoxy the best choice for me?</a>
60 <span class="APPLICATION">Privoxy</span> is certainly a good
61 choice, especially for those who want more control and security.
62 Those with the willingness to read the documentation and the
63 ability to fine-tune their installation will benefit the most.
66 One of <span class="APPLICATION">Privoxy's</span> strengths is that
67 it is highly configurable giving you the ability to completely
68 personalize your installation. Being familiar with, or at least
69 having an interest in learning about <a href=
70 "http://en.wikipedia.org/wiki/Http" target="_top">HTTP</a> and
71 other networking protocols, <a href=
72 "http://en.wikipedia.org/wiki/Html" target="_top">HTML</a>, and <a
73 href="http://en.wikipedia.org/wiki/Regular_expressions" target=
74 "_top"><span class="QUOTE">"Regular Expressions"</span></a> will be
75 a big plus and will help you get the most out of <span class=
76 "APPLICATION">Privoxy</span>. A new installation just includes a
77 very basic configuration. The user should take this as a starting
78 point only, and enhance it as he or she sees fit. In fact, the user
79 is encouraged, and expected to, fine-tune the configuration.
82 Much of <span class="APPLICATION">Privoxy's</span> configuration
83 can be done with a <a href=
84 "http://en.wikipedia.org/wiki/Web_browser" target="_top">Web
85 browser</a>. But there are areas where configuration is done using
86 a <a href="http://en.wikipedia.org/wiki/Text_editors" target=
87 "_top">text editor</a> to edit configuration files. Also note that
88 the web-based action editor doesn't use authentication and should
89 only be enabled in environments where all clients with access to
90 <span class="APPLICATION">Privoxy</span> listening port can be
96 <a name="PROXYMORON">1.3. What is a <span class=
97 "QUOTE">"proxy"</span>? How does Privoxy work?</a>
100 A <a href="http://en.wikipedia.org/wiki/Proxy_server" target=
101 "_top">web proxy</a> is a service, based on a software such as
102 <span class="APPLICATION">Privoxy</span>, that clients (i.e.
103 browsers) can use instead of connecting to web servers directly.
104 The clients then ask the proxy to request objects (web pages,
105 images, movies etc) on their behalf and to forward the data to the
106 clients. It is a <span class="QUOTE">"go-between"</span>. For
107 details, see <a href="http://en.wikipedia.org/wiki/Proxy_server"
108 target="_top">Wikipedia's proxy definition</a>.
111 There are many reasons to use web proxies, such as security
112 (firewalling), efficiency (caching) and others, and there are any
113 number of proxies to accommodate those needs.
116 <span class="APPLICATION">Privoxy</span> is a proxy that is
117 primarily focused on privacy enhancement, ad and junk elimination
118 and freeing the user from restrictions placed on his activities.
119 Sitting between your browser(s) and the Internet, it is in a
120 perfect position to filter outbound personal information that your
121 browser is leaking, as well as inbound junk. It uses a variety of
122 techniques to do this, all of which are under your complete control
123 via the various configuration files and options. Being a proxy also
124 makes it easier to share configurations among multiple browsers
130 <a name="OTHERSTUFF">1.4. Does Privoxy do anything more than ad
134 Yes, ad blocking is but one possible use. There are many, many ways
135 <span class="APPLICATION">Privoxy</span> can be used to sanitize
136 and customize web browsing.
141 <a name="NEWJB">1.5. What is this new version of <span class=
142 "QUOTE">"Junkbuster"</span>?</a>
145 A long time ago, there was the <span class="APPLICATION">Internet
146 Junkbuster</span>, by Anonymous Coders and Junkbusters Corporation.
147 This saved many users a lot of pain in the early days of web
148 advertising and user tracking.
151 But the web, its protocols and standards, and with it, the
152 techniques for forcing ads on users, give up autonomy over their
153 browsing, and for tracking them, keeps evolving. Unfortunately, the
154 <span class="APPLICATION">Internet Junkbuster</span> did not.
155 Version 2.0.2, published in 1998, was the last official release,
156 available from Junkbusters Corporation. Fortunately, it had been
157 released under the GNU <a href=
158 "http://www.gnu.org/licenses/old-licenses/gpl-2.0.html" target=
159 "_top">GPL</a>, which allowed further development by others.
162 So Stefan Waldherr started maintaining an improved version of the
163 software, to which eventually a number of people contributed
164 patches. It could already replace banners with a transparent image,
165 and had a first version of pop-up killing, but it was still very
166 closely based on the original, with all its limitations, such as
167 the lack of HTTP/1.1 support, flexible per-site configuration, or
168 content modification. The last release from this effort was version
169 2.0.2-10, published in 2000.
173 "https://www.privoxy.org/user-manual/copyright.html#AUTHORS"
174 target="_top">developers</a> picked up the thread, and started
175 turning the software inside out, upside down, and then reassembled
176 it, adding many <a href=
177 "https://www.privoxy.org/user-manual/introduction.html#FEATURES"
178 target="_top">new features</a> along the way.
181 The result of this is <span class="APPLICATION">Privoxy</span>,
182 whose first stable version, 3.0, was released August, 2002.
185 As of 2012 the Junkbusters Corporation's website
186 (http://www.junkbusters.com/) has been shut down, but Privoxy is
187 still actively maintained.
192 <a name="WHYPRIVOXY">1.6. Why <span class="QUOTE">"Privoxy"</span>?
193 Why change the name from Junkbuster at all?</a>
196 Though outdated, Junkbusters Corporation continued to offer their
197 original version of the <span class="APPLICATION">Internet
198 Junkbuster</span> for a while, so publishing our <span class=
199 "APPLICATION">Junkbuster</span>-derived software under the same
200 name would have led to confusion.
203 There were also potential legal reasons not to use the <span class=
204 "APPLICATION">Junkbuster</span> name, as it was (and maybe still
205 is) a registered trademark of Junkbusters Corporation. There were,
206 however, no objections from Junkbusters Corporation to the <span
207 class="APPLICATION">Privoxy</span> project itself, and they, in
208 fact, shared our ideals and goals.
211 The Privoxy developers also believed that there were so many
212 improvements over the original code, that it was time to make a
213 clean break from the past and make a name in their own right.
216 <span class="APPLICATION">Privoxy</span> is the <span class=
217 "QUOTE">"<span class="emphasis"><i class="EMPHASIS">Privacy
218 Enhancing Proxy</i></span>"</span>. Also, its content modification
219 and junk suppression gives <span class="emphasis"><i class=
220 "EMPHASIS">you</i></span>, the user, more control, more freedom,
221 and allows you to browse your personal and <span class=
222 "QUOTE">"<span class="emphasis"><i class=
223 "EMPHASIS">private</i></span> edition"</span> of the web.
228 <a name="DIFFERS">1.7. How does Privoxy differ from the old
232 <span class="APPLICATION">Privoxy</span> picks up where <span
233 class="APPLICATION">Junkbuster</span> left off. <span class=
234 "APPLICATION">Privoxy</span> still blocks ads and banners, still
235 manages <a href="http://en.wikipedia.org/wiki/Browser_cookie"
236 target="_top">cookies</a>, and still helps protect your privacy.
237 But, most of these features have been enhanced, and many new ones
238 have been added, all in the same vein.
241 <span class="APPLICATION">Privoxy</span>'s new features include:
248 Supports "Connection: keep-alive". Outgoing connections can be
249 kept alive independently from the client.
254 Supports IPv6, provided the operating system does so too, and
255 the configure script detects it.
260 Supports tagging which allows to change the behaviour based on
261 client and server headers.
266 Can be run as an "intercepting" proxy, which obviates the need
267 to configure browsers individually.
272 Sophisticated actions and filters for manipulating both server
278 Can be chained with other proxies.
283 Integrated browser-based configuration and control utility at
284 <a href="http://config.privoxy.org/" target=
285 "_top">http://config.privoxy.org/</a> (shortcut: <a href=
286 "http://p.p/" target="_top">http://p.p/</a>). Browser-based
287 tracing of rule and filter effects. Remote toggling.
292 Web page filtering (text replacements, removes banners based on
293 size, invisible <span class="QUOTE">"web-bugs"</span> and HTML
299 Modularized configuration that allows for standard settings and
300 user settings to reside in separate files, so that installing
301 updated actions files won't overwrite individual user settings.
306 Support for Perl Compatible Regular Expressions in the
307 configuration files, and a more sophisticated and flexible
308 configuration syntax.
318 Bypass many click-tracking scripts (avoids script redirection).
323 User-customizable HTML templates for most proxy-generated pages
324 (e.g. "blocked" page).
329 Auto-detection and re-reading of config file changes.
334 Most features are controllable on a per-site or per-location
340 Many smaller new features added, limitations and bugs removed.
347 <a name="WHATSANAD">1.8. How does Privoxy know what is an ad, and
351 <span class="APPLICATION">Privoxy</span>'s approach to blocking ads
355 First, there are certain patterns in the <span class="emphasis"><i
356 class="EMPHASIS">locations</i></span> (URLs) of banner images. This
357 applies to both the path (you wouldn't guess how many web sites
358 serve their banners from a directory called <span class=
359 "QUOTE">"banners"</span>!) and the host (blocking the big banner
360 hosting services like doublecklick.net already helps a lot). <span
361 class="APPLICATION">Privoxy</span> takes advantage of this fact by
362 using <a href="../user-manual/actions-file.html#AF-PATTERNS"
363 target="_top">URL patterns</a> to sort out and block the requests
364 for things that sound like they would be ads or banners.
367 Second, banners tend to come in certain <span class="emphasis"><i
368 class="EMPHASIS">sizes</i></span>. But you can't tell the size of
369 an image by its URL without downloading it, and if you do, it's too
370 late to save bandwidth. Therefore, <span class=
371 "APPLICATION">Privoxy</span> also inspects the HTML sources of web
372 pages while they are loaded, and replaces references to images with
373 standard banner sizes by dummy references, so that your browser
374 doesn't request them anymore in the first place.
377 Both of this involves a certain amount of guesswork and is, of
378 course, freely and readily configurable.
383 <a name="MISTAKES">1.9. Can Privoxy make mistakes? This does not
384 sound very scientific.</a>
387 Actually, it's a black art ;-) And yes, it is always possible to
388 have a broad rule accidentally block or change something by
389 mistake. You will almost surely run into such situations at some
390 point. It is tricky writing rules to cover every conceivable
391 possibility, and not occasionally get false positives.
394 But this should not be a big concern since the <span class=
395 "APPLICATION">Privoxy</span> configuration is very flexible, and
396 includes tools to help identify these types of situations so they
397 can be addressed as needed, allowing you to customize your
398 installation. (<a href="trouble.html#BADSITE">See the
399 Troubleshooting section below</a>.)
404 <a name="CONFIGORNOT">1.10. Will I have to configure Privoxy before
408 That depends on your expectations. The default installation should
409 give you a good starting point, and block <span class="emphasis"><i
410 class="EMPHASIS">most</i></span> ads and unwanted content, but many
411 of the more advanced features are off by default, and require you
415 You do have to set up your browser to use <span class=
416 "APPLICATION">Privoxy</span> (see the <a href=
417 "installation.html#FIRSTSTEP">Installation section below</a>).
420 And you will certainly run into situations where there are false
421 positives, or ads not being blocked that you may not want to see.
422 In these cases, you would certainly benefit by customizing <span
423 class="APPLICATION">Privoxy's</span> configuration to more closely
424 match your individual situation. And we encourage you to do this.
425 This is where the real power of <span class=
426 "APPLICATION">Privoxy</span> lies!
431 <a name="LAN">1.11. Can Privoxy run as a server on a network?</a>
434 Yes, <span class="APPLICATION">Privoxy</span> runs as a server
435 already, and can easily be configured to <span class=
436 "QUOTE">"serve"</span> more than one client. See <a href=
437 "configuration.html#LANCONFIG">How can I set up Privoxy to act as a
438 proxy for my LAN</a> below.
443 <a name="BROWSERS2">1.12. My browser does the same things as
444 Privoxy. Why should I use Privoxy at all?</a>
447 Modern browsers do indeed have <span class="emphasis"><i class=
448 "EMPHASIS">some</i></span> of the same functionality as <span
449 class="APPLICATION">Privoxy</span>. Maybe this is adequate for you.
450 But <span class="APPLICATION">Privoxy</span> is very versatile and
451 powerful, and can probably do a number of things your browser just
455 In addition, a proxy is good choice if you use multiple browsers,
456 or have a LAN with multiple computers since <span class=
457 "APPLICATION">Privoxy</span> can run as a server application. This
458 way all the configuration is in one place, and you don't have to
459 maintain a similar configuration for possibly many browsers or
463 Note, however, that it's recommended to leverage both your
464 browser's and <span class="APPLICATION">Privoxy's</span> privacy
465 enhancing features at the same time. While your browser probably
466 lacks some features <span class="APPLICATION">Privoxy</span>
467 offers, it should also be able to do some things more reliably, for
468 example restricting and suppressing JavaScript.
473 <a name="WHYTRUST">1.13. Why should I trust Privoxy?</a>
476 The most important reason is because you have access to <span
477 class="emphasis"><i class="EMPHASIS">everything</i></span>, and you
478 can control everything. You can check every line of every
479 configuration file yourself. You can check every last bit of source
480 code should you desire. And even if you can't read code, there
481 should be some comfort in knowing that other people can, and do
482 read it. You can build the software from scratch, if you want, so
483 that you know the executable is clean, and that it is <span class=
484 "emphasis"><i class="EMPHASIS">yours</i></span>. In fact, we
485 encourage this level of scrutiny. It is one reason we use <span
486 class="APPLICATION">Privoxy</span> ourselves.
491 <a name="LICENSE">1.14. Is there is a license or fee? What about a
492 warranty? Registration?</a>
495 <span class="APPLICATION">Privoxy</span> is free software and
496 licensed under the <a href=
497 "http://www.gnu.org/licenses/old-licenses/gpl-2.0.html" target=
498 "_top">GNU General Public License (GPL) version 2</a>. It is free
499 to use, copy, modify or distribute as you wish under the terms of
500 this license. Please see the <a href="copyright.html">Copyright</a>
501 section for more information on the license and copyright. Or the
502 <tt class="FILENAME">LICENSE</tt> file that should be included.
505 There is <span class="emphasis"><i class="EMPHASIS">no
506 warranty</i></span> of any kind, expressed, implied or otherwise.
507 That is something that would cost real money ;-) There is no
513 <a name="SPYWARE">1.15. Can Privoxy remove spyware? Adware?
517 No, at least not reliably enough to trust it. <span class=
518 "APPLICATION">Privoxy</span> is not designed to be a malware
519 removal tool and the default configuration doesn't even try to
520 filter out any malware.
523 <span class="APPLICATION">Privoxy</span> could help prevent contact
524 from (known) sites that use such tactics with appropriate
525 configuration rules, and thus could conceivably prevent
526 contamination from such sites. However, keeping such a
527 configuration up to date would require a lot of time and effort
528 that would be better spend on keeping your software itself up to
529 date so it doesn't have known vulnerabilities.
534 <a name="OTHERADS">1.16. Can I use Privoxy with other ad-blocking
538 <span class="APPLICATION">Privoxy</span> should work fine with
539 other proxies and other software in general.
542 But it is probably not necessary to use <span class=
543 "APPLICATION">Privoxy</span> in conjunction with other ad-blocking
544 products, and this could conceivably cause undesirable results. It
545 might be better to choose one software or the other and work a
546 little to tweak its configuration to your liking.
549 Note that this is an advice specific to ad blocking.
554 <a name="HELP-THE-DEVELOPERS">1.17. I would like to help you, what
559 <a name="PARTICIPATE">1.17.1. Would you like to participate?</a>
562 Well, we <span class="emphasis"><i class=
563 "EMPHASIS">always</i></span> need help. There is something for
564 everybody who wants to help us. We welcome new developers,
565 packagers, testers, documentation writers or really anyone with a
566 desire to help in any way. You <span class="emphasis"><i class=
567 "EMPHASIS">DO NOT</i></span> need to be a <span class=
568 "QUOTE">"programmer"</span>. There are many other tasks
569 available. In fact, the programmers often can't spend as much
570 time programming because of some of the other, more mundane
571 things that need to be done, like checking the Tracker feedback
572 sections or responding to user questions on the mailing lists.
575 So first thing, subscribe to the <a href=
576 "https://lists.privoxy.org/mailman/listinfo/privoxy-users"
577 target="_top">Privoxy Users</a> or the <a href=
578 "https://lists.privoxy.org/mailman/listinfo/privoxy-devel"
579 target="_top">Privoxy Developers</a> mailing list, join the
580 discussion, help out other users, provide general feedback or
581 report problems you noticed.
584 If you intend to help out with the trackers, you also might want
585 to <a href="https://sourceforge.net/user/registration" target=
586 "_top">get an account on SourceForge.net</a> so we don't confuse
587 you with the other name-less users.
590 We also have a <a href="../developer-manual/index.html" target=
591 "_top">Developer's Manual</a>. While it is partly out of date,
592 it's still worth reading.
596 "http://ijbswa.cvs.sourceforge.net/viewvc/ijbswa/current/TODO?view=markup"
597 target="_top">TODO list</a> may be of interest to you as well.
598 Please let us know if you want to work on one of the items
604 <a name="DONATE">1.17.2. Would you like to donate?</a>
607 Donations are welcome. Our <a href=
608 "http://ijbswa.cvs.sourceforge.net/viewvc/ijbswa/current/TODO?view=markup"
609 target="_top">TODO list</a> is rather long and being able to pay
610 one (or more) developers to work on Privoxy would make a huge
611 difference, even if it was only for a couple of weeks. Donations
612 may also be used for Privoxy-related travel expenses (for example
613 to attend conferences), for hardware used for Privoxy development
614 and for hosting expenses etc.
617 <span class="APPLICATION">Privoxy</span> is an associated project
618 of <a href="http://www.spi-inc.org/" target="_top">Software in
619 the Public Interest (SPI)</a>, which allows us to receive
620 tax-deductible donations in the United States. If you want to
621 donate through SPI, please use <a href=
622 "http://www.spi-inc.org/donations" target="_top">SPI's donation
623 page</a> to see what the options are.
626 You can also donate to Privoxy using a bank account or a "Paypal"
629 <p class="LITERALLAYOUT">
630 Name on account: <a href=
631 "https://www.zwiebelfreunde.de/" target="_top">Zwiebelfreunde
633 IBAN: DE95430609671126825604<br>
634 BIC: GENODEM1GLS<br>
635 Bank: GLS Bank
637 <p class="LITERALLAYOUT">
638 "Paypal" address: privoxy@zwiebelfreunde.de
641 Donations made through Zwiebelfreunde e.V. are tax-deductible in
642 Germany and other countries that recognize German charitable
643 clubs. Feel free to use the Subject field to provide a name to be
644 credited and a list of TODO list items you are interested in the
645 most. For example: Max Mustermann: #16, #1, #14.
648 Note that donations made through Zwiebelfreunde e.V. currently
649 can't be checked automatically so you may not get credited right
650 away. The credits currently reflect donations received before
654 If you have any questions regarding donations please mail to
655 either the public user mailing list or, if it's a private matter,
656 to <a href="mailto:fk@fabiankeil.de" target="_top">Fabian
657 Keil</a> (Privoxy's SPI liaison) directly.
663 <a name="SPONSOR">1.18. How can I become a sponsor and get my logo
664 or link on privoxy.org?</a>
667 We are currently offering the following sponsor levels as an
670 <div class="VARIABLELIST">
673 Gold (10000 EUR/year)
677 Logo shown at the bottom of the <a href=
678 "https://www.privoxy.org/" target="_top">Privoxy
679 homepage</a>. Logo, link and self description on the <a href=
680 "https://www.privoxy.org/sponsors/" target="_top">sponsor
685 Silver (1000 EUR/year)
689 Logo shown randomly at the bottom of the <a href=
690 "https://www.privoxy.org/" target="_top">Privoxy
691 homepage</a>. Logo, link and self description on the <a href=
692 "https://www.privoxy.org/sponsors/" target="_top">sponsor
697 Bronze (500 EUR/year)
701 Logo and link on the <a href=
702 "https://www.privoxy.org/sponsors/" target="_top">sponsor
709 The logo sizes depend on the sponsor level. Logos are served from
710 our server, no requests are made to the sponsor website unless the
711 links are being used.
714 The details may change over time but changes will only affect new
715 sponsors (or existing sponsors that explicitly agreed to the
719 If you want to become a sponsor, please contact <a href=
720 "mailto:fk@fabiankeil.de" target="_top">Fabian Keil</a>. New
721 sponsors are only accepted if no developer objects.
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