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diff --git a/doc/librejs.info b/doc/librejs.info new file mode 100644 index 0000000..fb706b5 --- /dev/null +++ b/doc/librejs.info @@ -0,0 +1,1243 @@ +This is librejs.info, produced by makeinfo version 5.2 from +librejs.texi. + +This manual is for GNU LibreJS (version 6.0.8.20150117, 17 January +2015), a GNU IceCat extension to detect and block nonfree nontrivial +JavaScript on webpages. + + Copyright (C) 2011 2012 2014 Loic J. Duros + + Permission is granted to copy, distribute and/or modify this + document under the terms of the GNU Free Documentation License, + Version 1.3 or any later version published by the Free Software + Foundation; with no Invariant Sections, with no Front-Cover Texts, + and with no Back-Cover Texts. A copy of the license is included in + the section entitled "GNU Free Documentation License". +INFO-DIR-SECTION GNUzilla +START-INFO-DIR-ENTRY +* LibreJS: (librejs). Detect nonfree nontrivial in GNU Icecat +END-INFO-DIR-ENTRY + + +File: librejs.info, Node: Top, Next: Overview, Up: (dir) + +LibreJS +******* + +This manual is for GNU LibreJS (version 6.0.8.20150117, 17 January +2015). + +* Menu: + +* Overview:: General purpose and information. +* Disclaimer:: Emphasize what LibreJS does and does not. +* Installation:: Installing LibreJS from source. +* How to Use:: How to use LibreJS in IceCat. +* JavaScript Detection:: How LibreJS detects nontrivial Javascript. +* Free Licenses Detection:: List of licenses detected by LibreJS. +* Setting Your JavaScript Free:: Information for website owners/maintainers. +* Installation Requirements:: Requirements to build and install LibreJS. +* LibreJS Internals:: How LibreJS works under the hood. +* Tests:: Test LibreJS and better understand it. +* GNU Free Documentation License:: Copying and sharing this documentation. + + +File: librejs.info, Node: Overview, Next: Disclaimer, Prev: Top, Up: Top + +1 Overview +********** + +GNU LibreJS --an add-on for GNU IceCat and Mozilla Firefox-- detects and +blocks nonfree nontrivial JavaScript while allowing its execution on +pages containing code that is either trivial and/or free. + + Many websites run nontrivial JavaScript on your computer. Some use +it for complex tasks; many use it gratuitously for minor jobs that could +be done easily with plain HTML. Sometimes this JavaScript code is +malicious. Either way, the JavaScript code is often nonfree. For +explanation of the issue, see "The JavaScript +Trap"(<http://www.gnu.org/philosophy/javascript-trap.html>). + + If you care about freedom in your computing, and don't wish to let +all and sundry make you run nonfree programs, now you can prevent it by +using LibreJS. + + +File: librejs.info, Node: Disclaimer, Next: Installation, Prev: Overview, Up: Top + +2 Disclaimer +************ + + * LibreJS is not a security tool. Its goal is to detect nonfree + nontrivial JavaScript, and it currently does not detect whether + free or trivial code is malicious or not. Other free Mozilla + extensions and add-ons may be available for this purpose. + + * LibreJS is always a work in progress. If you find a bug, please + report it to <bug-librejs@gnu.org>. + + +File: librejs.info, Node: Installation, Next: How to Use, Prev: Disclaimer, Up: Top + +3 Installation +************** + +You can install LibreJS directly using a generated 'librejs.xpi' file, +or by building it from source. + +3.1 Building the Package +======================== + +After enabling the Add-on SDK, you should be able to use the 'make' +command to build LibreJS from source. + + After running 'make', a new file, 'librejs.xpi' should be generated. +This is the file that can be installed in a Mozilla browser. + +3.2 Installing LibreJS +====================== + +To install the add-on for all users, run: + sudo make install + + or as root: + make install + + Next time you open a Mozilla-browser as a user of your system, you +should be notified that a new add-on (in this case, LibreJS) as been +installed and whether to allow it to run or not. + + +File: librejs.info, Node: How to Use, Next: JavaScript Detection, Prev: Installation, Up: Top + +4 How to Use +************ + +4.1 LibreJS in action +===================== + +After installing the add-on, you will see the LibreJS widget in the +add-on bar at the bottom of the browser window. After loading a page, +left-click on the widget to view the deactivated JavaScript code from +the page (both on page and external) and, if applicable, the scripts +that were accepted. + +4.2 Complaint Feature +===================== + +It is very important to complain when a site has nonfree JavaScript +code, especially if it won't work without that code. LibreJS makes it +easy to complain by heuristically finding where to send the complaint. + + When nonfree/nontrivial code is detected in a page, LibreJS attempts +to find a relevant contact link or email for the website you are +visiting. In order to do so, it will attempt to visit a few links from +the current page (for instance, a link labeled "contact" on the same +domain as the current page, ...) + + LibreJS detects contact pages, email addresses that are likely to be +owned by the maintainer of the site, Twitter and identi.ca links, and +phone numbers. + + After LibreJS detects any of the above, a "Complain" tab will appear +on the right of your web browser. When you click on this tab, a large +panel will appear with contact information. Ideally, at the top you +will find the email address of the maintainer, labeled as the "Email you +should use". + + When you complain to the website for their nonfree nontrivial +JavaScript, provide them with the link to the JavaScript Trap essay so +that they can get more information on what the issue is and how they can +solve it on their own site. + + LibreJS includes a default subject line and body for the complaint +email, with a link to the JavaScript Trap essay. This can be configured +in the LibreJS add-on preferences in your web browser. + +4.3 Options +=========== + +"Whitelist" + LibreJS lets you whitelist domain names and subdomains to bypass + the regular JavaScript check. This might be useful, for example, + if you are running your own code in a local web server. In order + to add a whitelisted domain or url, go to Tools >> Add-ons, or + press 'Control + Shift + A'. Inside the add-on window, click on + "Extensions", and in the list, where you see LibreJS, click on the + "Preferences" button. You will see an input field labeled + "Whitelist". In the field, enter comma-separated domain names. Do + not enter the protocol. For instance to whitelist all the pages of + <http://www.gnu.org> and <https://gnu.org>, enter 'gnu.org'. To + allow all subdomains from gnu.org, enter: '*.gnu.org'. This will + match such sites as <http://savannah.gnu.org> and + <http://audio-video.gnu.org>. + +"Complaint tab" + This specifies whether the complaint tab appears when a site is + running nonfree JavaScript. + +"Display notifications of JavaScript analysis" + This option enables an info bar of realtime JavaScript analysis. + +"Complaint email subject" + Configure the default subject used in complaint emails. + +"Complaint email body" + Configure the default body used in complaint emails. + + +File: librejs.info, Node: JavaScript Detection, Next: Free Licenses Detection, Prev: How to Use, Up: Top + +5 JavaScript Detection +********************** + + LibreJS considers JavaScript on a page nontrivial if any of the + following are true: + + * It makes an AJAX request or is loaded along with scripts that make + an AJAX request, + + * It loads external scripts dynamically or is loaded along with + scripts that do, + + * It defines functions or methods and either loads an external script + (from HTML) or is loaded as one, + + * It uses dynamic JavaScript constructs that are difficult to analyze + without interpreting the program or is loaded along with scripts + that use such constructs. These constructs are: + * Using the eval function + * Calling methods with the square bracket notation + * Using any other construct than a string literal with certain + methods ('Obj.write', 'Obj.createElement', ...). + + In practice, the JavaScript code in your page may be found trivial by +LibreJS if, as a whole: + + * It does not define functions and it does not load external scripts + (with the HTML src attribute in a '<script>' tag). + + * It does not make AJAX calls. + + * It does not load external scripts with dynamic constructs. + + * It does not use constructs that may be used to do any of the above + in a non-obvious way (use of the 'eval()' method, use of square + bracket method calls, use of concatenation with certain constructs + or method calls, ...). + + However, in some instances, you may be required by LibreJS to add a +stylized comment to JavaScript code that may be otherwise trivial. + + When an external file defines a function, it becomes available to all +other external scripts. That is the case if another script defines a +function that makes AJAX calls, when an external script loads other +scripts dynamically (which in turn could also make AJAX calls, ...), or +when a script is written with constructs that may do any of these. + + For instance, if your page contains the following: + <script src="jquery.js"></script> + <script> + $.doSomething(); + </script> + + While '$.doSomething();' may seem trivial, you will nevertheless have +to add a stylized license comment on your main HTML page because the +external script (in this case jQuery) has been found to define methods +that make AJAX calls. '$.doSomething()' might make an AJAX call, and +LibreJS does not check for that. The rule of thumb is that when you use +a library or code that handles AJAX, JSON, JSONP, the loading of scripts +dynamically, you should have license mentions for all your JavaScript +files and for your main page regardless. In practice this is a case +that happens very often with code that uses libraries. + + In practice also, the JavaScript code in an external file (an +external '.js' file loaded on your page) may be found trivial if it does +not define functions/methods. + + And in the same manner it will be considered nontrivial if AJAX +calls, dynamic script loading, or non-obvious dynamic JavaScript +constructs are used in another script. + + If your JavaScript code makes AJAX requests, it's important to get an +accurate "Content-Type" in the response from the server. For example, +if you're using JSON, set it to 'application/json'. This is because +LibreJS alters the content of 'text/html' responses. + + +File: librejs.info, Node: Free Licenses Detection, Next: Setting Your JavaScript Free, Prev: JavaScript Detection, Up: Top + +6 Free Licenses Detection +************************* + +6.1 Detected Free Licenses +========================== + +In order for a file to be detected as free, the license notice should +appear in a JavaScript file above all code, at the very top of the file. + + For inline JavaScript code inside '<script>' tags in HTML pages, the +license notice should appear once per page as a comment inside a +'<script>' tag, before all the code in that script. When the only +inline JavaScript code is within element attributes ('onload', +'onclick'), place the license notice in an otherwise empty '<script>' at +the top of the page. This is sometimes needed when an external script +performs AJAX calls or embeds scripts dynamically, and the only inline +JavaScript is an event attribute making a method call, e.g.: '<body +onload="methodCall('remote-data.xml');">' + + When people speak of the "MIT license" they mean either the X11 +license or the Expat license. Please see which license the code uses, +and label it accordingly. + + Currently LibreJS checks for the following licenses: + + * Creative Commons CC0 1.0 Universal + * Identifier: 'CC0-1.0' + * URL: + <http://creativecommons.org/publicdomain/zero/1.0/legalcode> + * Magnet link: + 'magnet:?xt=urn:btih:90dc5c0be029de84e523b9b3922520e79e0e6f08&dn=cc0.txt' + + * Public Domain + * Public domain is not a license (see + <https://www.gnu.org/licenses/license-list.html#PublicDomain>). + If you want to release your work to the public domain, the FSF + recommends using CC0. + * Magnet Link: + 'magnet:?xt=urn:btih:e95b018ef3580986a04669f1b5879592219e2a7a&dn=public-domain.txt' + + * GNU General Public License (GPL) version 2 + * Identifier: 'GNU-GPL-2.0' + * URL: <http://www.gnu.org/licenses/gpl-2.0.html> + * Magnet link: + 'magnet:?xt=urn:btih:cf05388f2679ee054f2beb29a391d25f4e673ac3&dn=gpl-2.0.txt' + + * GNU General Public License (GPL) version 3 + * Identifier: 'GNU-GPL-3.0' + * URL: <http://www.gnu.org/licenses/gpl-3.0.html> + * Magnet link: + 'magnet:?xt=urn:btih:1f739d935676111cfff4b4693e3816e664797050&dn=gpl-3.0.txt' + + * Apache License, Version 2.0 + * Identifier: 'Apache-2.0' + * URL: <http://www.apache.org/licenses/LICENSE-2.0> + * Magnet link: + 'magnet:?xt=urn:btih:8e4f440f4c65981c5bf93c76d35135ba5064d8b7&dn=apache-2.0.txt' + + * GNU Lesser General Public License, version 2.1 + * Identifier: 'GNU-LGPL-2.1' + * URL: <http://www.gnu.org/licenses/lgpl-2.1.html> + * Magnet link: + 'magnet:?xt=urn:btih:5de60da917303dbfad4f93fb1b985ced5a89eac2&dn=lgpl-2.1.txt' + + * GNU Lesser General Public License, version 3 + * Identifier: 'GNU-LGPL-3.0' + * URL: <http://www.gnu.org/licenses/lgpl-3.0.html> + * Magnet link: + 'magnet:?xt=urn:btih:0ef1b8170b3b615170ff270def6427c317705f85&dn=lgpl-3.0.txt' + + * GNU Affero General Public License, version 3 + * Identifier: 'GNU-AGPL-3.0' + * URL: <http://www.gnu.org/licenses/agpl-3.0.html> + * Magnet link: + 'magnet:?xt=urn:btih:0b31508aeb0634b347b8270c7bee4d411b5d4109&dn=agpl-3.0.txt' + + * Boost Software License + * URL: <http://www.boost.org/LICENSE_1_0.txt> + * Magnet link: + 'magnet:?xt=urn:btih:89a97c535628232f2f3888c2b7b8ffd4c078cec0&dn=Boost-1.0.txt' + + * BSD 3-Clause License + * URL: <http://opensource.org/licenses/BSD-3-Clause> + * Magnet link: + 'magnet:?xt=urn:btih:c80d50af7d3db9be66a4d0a86db0286e4fd33292&dn=bsd-3-clause.txt' + + * Eclipse Public License 1.0 + * Identifier: 'EPL-1.0' + * URL: <http://www.eclipse.org/legal/epl-v10.html> + * Magnet link: + 'magnet:?xt=urn:btih:4c6a2ad0018cd461e9b0fc44e1b340d2c1828b22&dn=epl-1.0.txt' + + * Mozilla Public License 2.0 + * Identifier: 'MPL-2.0' + * URL: <http://www.mozilla.org/MPL/2.0> + * Magnet link: + 'magnet:?xt=urn:btih:3877d6d54b3accd4bc32f8a48bf32ebc0901502a&dn=mpl-2.0.txt' + + * Expat License (sometimes called the MIT license) + * Identifier: 'Expat' + * URL: <http://www.jclark.com/xml/copying.txt> + * Magnet link: + 'magnet:?xt=urn:btih:d3d9a9a6595521f9666a5e94cc830dab83b65699&dn=expat.txt' + + * X11 License + * Magnet link: + 'magnet:?xt=urn:btih:5305d91886084f776adcf57509a648432709a7c7&dn=x11.txt' + + * XFree86 License + * Identifier: 'Modified-BSD' + * URLs: <http://www.xfree86.org/3.3.6/COPYRIGHT2.html#3> + <http://www.xfree86.org/current/LICENSE4.html> + * Magnet link: + 'magnet:?xt=urn:btih:12f2ec9e8de2a3b0002a33d518d6010cc8ab2ae9&dn=xfree86.txt' + + * FreeBSD License + * URL: <http://www.freebsd.org/copyright/freebsd-license.html> + * Magnet link: + 'magnet:?xt=urn:btih:87f119ba0b429ba17a44b4bffcab33165ebdacc0&dn=freebsd.txt' + + * The ISC License + * URL: + <https://www.isc.org/downloads/software-support-policy/isc-license/> + * Magnet link: + 'magnet:?xt=urn:btih:b8999bbaf509c08d127678643c515b9ab0836bae&dn=ISC.txt' + + * Artistic License 2.0 + * URL: <http://www.perlfoundation.org/artistic_license_2_0> + * Magnet link: + 'magnet:?xt=urn:btih:54fd2283f9dbdf29466d2df1a98bf8f65cafe314&dn=artistic-2.0.txt' + + * CPAL 1.0 + * Identifier: 'CPAL-1.0' + * URL: <http://opensource.org/licenses/cpal_1.0> + * Magnet link: + 'magnet:?xt=urn:btih:84143bc45939fc8fa42921d619a95462c2031c5c&dn=cpal-1.0.txt' + +6.2 Undetected Free Licenses +============================ + +If you are using a free license that isn't detected by LibreJS and isn't +listed in the previous section, please send a message to +<bug-librejs@gnu.org> regarding this license, where code released under +this license can be found, and where to find the license text and +information. + + Many free licenses are listed in this page: +<http://www.gnu.org/licenses/license-list.html> + + +File: librejs.info, Node: Setting Your JavaScript Free, Next: Installation Requirements, Prev: Free Licenses Detection, Up: Top + +7 Setting Your JavaScript Free +****************************** + +The first step is releasing your JavaScript under a free license. If +you are already using a free library, or you're not using any +third-party libraries, it might only take a few minutes. + + All JavaScript code on a web page (inline, on-page, and external) +shares a common scope. Thus, code is generally either rejected or +accepted as a whole by LibreJS. If some JavaScript code is found to be +nontrivial and nonfree, then most of the time, all the the rest is +discarded as well. + + On your website, take a look at your HTML source. You can identify +distinct pieces of JavaScript that might be free and some other that are +nonfree. + + _Tip_: By running LibreJS on your page, you will get a list of all +the JavaScript that was blocked. This gives you an overview of the +JavaScript in your page. + + Imagine a page that contains several pieces of JavaScript from +various sources: + * On top, within the '<head>' tag, it includes jQuery + + * Then, some JavaScript code that you have written + + * At the bottom, a JavaScript-based Facebook widget + + * Also, there's some analytics tracking code + +"JavaScript that is already free" + First, you must ensure that the library is free. If the file + contains a copyright and a license notice, you won't need to look + any further. But if there's no mention of the license, or if it's + too brief, you'll have to look for a COPYING or LICENSE file within + the original library's source package, or on the library's official + website. + +"Your own JavaScript" + The free license given to your code should be compatible with the + rest of the JavaScript on a page. A good way to check is to read + up on them: <http://www.gnu.org/licenses/license-list.html> + +"Nonfree JavaScript" + This might be the case with an analytics tracker, social media + widgets, and code that runs ads. Removing these pieces of code + from your site is required to have the rest accepted as free. + There are often alternatives to nonfree libraries or to third-party + services: + + * If you have used nonfree third-party code as the base to write + your own code, try to find a free alternative. + + * If you're using a third-party service such as an analytics + service, replace it with a free alternative like Piwik. + + * If you can't find free JavaScript that has already been + developed, write it yourself! Who knows, your own solution + might be the start of a brilliant project! + +7.1 JavaScript Web Labels +========================= + +One way to make your website work with LibreJS is by defining a +JavaScript Web Labels table. + + A JavaScript Web Labels table is informative to both site visitors +and the LibreJS program. You make a Web Labels table on a new HTML page +that's linked to from your main page. The table lists each of your +site's JavaScript files, that file's corresponding human-readable source +file, and the canonical url of its free license. + + When using a JavaScript Web Labels table for your own files, it's +important to put a copying permission statement at the top of each +source file listed in right-most column of the Web Labels table. For +info on how properly release your code as free software, see +<https://www.gnu.org/licenses/gpl-howto.html>. Future versions of +LibreJS will require a copying permission statement or other license +notice for source files listed in a Web Labels table. + + More information on JavaScript Web Labels is detailed here: +<https://www.gnu.org/software/librejs/free-your-javascript.html#step3> +and here: <https://www.gnu.org/licenses/javascript-labels.html>. + +7.1.1 Specifying multiple licenses for a single JavaScript file +--------------------------------------------------------------- + +If you compile or concatenate your JavaScript into a single file, the +source files you're combining may be released under different licenses. +You can specify multiple licenses for the file in a JavaScript Web +Labels table, like this: + +<table id="jslicense-labels1"> + <tr> + <td><a href="all.min.js">all.min.js</a></td> + <td> + <a href="http://www.gnu.org/licenses/gpl-3.0.html" + >GNU-GPL-3.0-or-later</a> + <br /> + <a href="http://www.apache.org/licenses/LICENSE-2.0" + >Apache-2.0</a> + </td> + <td> + <a href="gpl-script.js">gpl-script.js</a> + <br /> + <a href="apache-script.js">apache-script.js</a> + </td> + </tr> +</table> + + The '<br />' tags just make the table more understandable when +looking at the rendered version of it on the license page. They aren't +required by LibreJS. + + If all the licenses contained in the second column are recognized by +LibreJS to be free licenses, then LibreJS will allow the file in the +first column to be run. + +7.2 Adding a stylized comment in your JavaScript files and on your page +======================================================================= + +See a "Convention for releasing free JavaScript programs" in the +JavaScript Trap <http://www.gnu.org/philosophy/javascript-trap.html> + + Adding this notice will ensure LibreJS will find the JavaScript file +to be free. The '@licstart' and '@licend' lines at the beginning and +end of the stylized comment are necessary to make a clear statement that +the _entire code_ in the file is free. This means that you must ensure +that no nonfree code was carelessly appended at the end of the file. + + In the main HTML page, the license notice covers JavaScript contained +in all '<script>' tags with on-page code and the inline JavaScript (in +event attributes such as onload, onclick, etc, ...). Since external +files have their own stylized comment, they are not covered by the +notice in the main HTML page. Make sure to identify all the licenses +available. LibreJS will only ensure it matches a notice of an allowed +license once, so the order does not matter, but the responsibility is on +you to make sure all code is under the free licenses mentioned between +'@licstart' and '@licend'. + + You should make _only_ one '@licstart' '@licend' comment in your +page, since it pertains to the entire code on page across all '<script>' +tags and inline html attributes. + +When you use the JavaScript Web Labels method, you should still include +a license notice at the top of each of your source files. This ensures +that if someone copies the file and uses it for something else, the +license remains intact. + + For more info on making your JavaScript LibreJS-compliant, see this +web page: +<https://www.gnu.org/software/librejs/free-your-javascript.html> + + +File: librejs.info, Node: Installation Requirements, Next: LibreJS Internals, Prev: Setting Your JavaScript Free, Up: Top + +Appendix A Installation Requirements +************************************ + +A.1 Mozilla Browser +=================== + +You will need one of the many flavors of the Mozilla browser to use +LibreJS. It can be installed on the following: + + GNU IceCat, Mozilla Firefox, Trisquel Abrowser, Debian Iceweasel. + + LibreJS works on these browsers starting from version 29. We +recommend that you use the latest version of your Mozilla browser. +LibreJS has been tested extensively on multiple GNU/Linux distributions, +but it is compatible any operating system as long as you're using a +compatible Mozilla browser. + +A.2 Mozilla's Add-on SDK +======================== + +LibreJS uses the Mozilla Add-on SDK (Software Development Kit), a set of +APIs and tools to create add-ons for Mozilla browsers. + + You do not need the Add-on SDK to use LibreJS xpi file or to install +it using the packaged version, but it is required in order to package +the LibreJS source code into an xpi file using 'make'. If you would +like to run the tests for LibreJS or make changes to the source files, +you will need the Add-on SDK as well. For the "make" command to work +properly, you must have the 'cfx' command available on your system from +the command line. + + The latest tarball for the Add-on SDK is available at: + + <https://ftp.mozilla.org/pub/mozilla.org/labs/jetpack/jetpack-sdk-latest.tar.gz> + + Instructions on how to get it working are available here: + + <https://addons.mozilla.org/en-US/developers/docs/sdk/latest/dev-guide/tutorials/installation.html> + + In order to use 'make' with LibreJS source, however, it is ideal to +have 'cfx' available at all times and for all users. + + An easy way to do this is to extract the contents of the tarball and +to place the files inside '/usr/lib/addon-sdk' and then creating a +symbolic link in '/usr/bin', as follows: + + sudo ln -s /usr/lib/addon-sdk/bin/cfx /usr/bin/cfx + + The 'cfx' command will then be available to all users. + + The Add-on SDK is released under the Mozilla Public License 2.0. + + +File: librejs.info, Node: LibreJS Internals, Next: Tests, Prev: Installation Requirements, Up: Top + +Appendix B LibreJS Internals +**************************** + +LibreJS intercepts HTTP responses and rewrites their contents after +analyzing JavaScript within them. It does not remove script nodes and +attributes from the page, but instead "deactivates" them by modifying +the 'type' and 'src' attributes on script elements and by moving the +contents of inline JavaScript attributes such as onClick into harmless +attributes. + + LibreJS detects the most common cases using the HTTP response method +described above, but in extremely rare cases, or when running code +locally, LibreJS cannot detect JavaScript during the response stage. + + To remedy this issue, and as a final safeguard, LibreJS takes a look +at the scripts that are about to be executed while the browser engine is +parsing the page. If the script is not found in a list of accepted +scripts populated earlier, the execution will be prevented. This is to +ensure content types that are not regular HTML (binhex with HTML in it, +...) and JavaScript do not fall through the cracks and get executed. + + +File: librejs.info, Node: Tests, Next: GNU Free Documentation License, Prev: LibreJS Internals, Up: Top + +Appendix C Tests +**************** + +In order to better understand how LibreJS works, you can try to visit +these pages with LibreJS installed and enabled and see how they are +being processed: + + * + <http://lduros.net/assets/librejs/tests/trivial-inline-trivial-external/> + This page contains trivial on-page JavaScript code, and an external + script that contains trivial JavaScript code. Therefore, all + JavaScript is being executed. + + * + <http://lduros.net/assets/librejs/tests/trivial-inline-nontrivial-external/> + The on-page script here is trivial and uses a built-in method, but + the external script in this page is nontrivial (defines a + function.) The external script is blocked, the inline script is + executed. + + * + <http://lduros.net/assets/librejs/tests/nontrivial-inline-trivial-external/> + This page contains nontrivial code on page, and trivial code in its + external page. All JavaScript is _removed_ from the page, and the + external script is never analyzed, since the nontrivial conditions + are already met in the page. + + * <http://lduros.net/assets/librejs/tests/free-inline-free-external/> + This page contains free on-page (GPL 3) JavaScript, and free + external Javascript. Therefore all JavaScript is being executed. + + * + <http://lduros.net/assets/librejs/tests/free-inline-nonfree-nontrivial-external/> + This page contains free on-page JavaScript. The external script + contains nonfree nontrivial JavaScript (AJAX request). The free + code that is inline is executed, but the external file is blocked. + + * <http://lduros.net/assets/librejs/tests/intrinsec-event/> This page + contains trivial on-page code, with an intrinsic event in an html + attribute (onload). All JavaScript is being executed. + + * + <http://lduros.net/assets/librejs/tests/trivial-inline-free-external-defines-function/> + This page contains on-page trivial JavaScript (only makes a window + alert and loads an external script using the html <script> tag with + the src attribute. The external script is free (GPL v3), and since + it is only nontrivial because it defines a function, the on-page + trivial code is allowed to use it. All JavaScript is being + executed. + + * + <http://lduros.net/assets/librejs/tests/trivial-inline-free-external-writes-script/> + This page contains trivial on-page JavaScript code, and loads an + external script that is free. Since no function is defined, the + external script is being analyzed. The external script is free. + Trivial here is not allowed because the external script, although + free, writes a script. The inline trivial script should also have + a free license notice for it to be interpreted. + + * + <http://lduros.net/assets/librejs/tests/shelltypist/demo/real-life-example-with-jquery-free.html> + This is a real-life example of a small jQuery plugin. The on-page + JavaScript code has a free license. The jQuery external file has a + free licensed. The shelltypist.js file has a free license as well. + All licenses are defined between '@licstart' and '@licend'. All + JavaScript is executed. + + * + <http://lduros.net/assets/librejs/tests/shelltypist/demo/same-page-without-free-license.html> + This is the same page than the previous example, except it does not + have a free license for the main HTML page on-page script. While + the actual code there is trivial, since jQuery defines methods that + make use of AJAX, trivial code is not allowed, and no JavaScript is + executed. + + * <http://lduros.net/assets/librejs/tests/test-labels/> This page + contains JavaScript (jQuery minified) that does not have proper + license information in the file, as it has no '@licstart' '@licend' + comment. It would be considered nonfree, however, the page itself + uses the JavaScript Web Labels method. On the page itself, you + will find a link labeled "JavaScript License Information", which + leads to a page that contains a properly formatted table with the + required data on the external JavaScript file. LibreJS visits this + link and determines the version of jQuery linked from the original + page is the one listed there, and flags it as free. All JavaScript + is executed (and the title should turn green.) + + +File: librejs.info, Node: GNU Free Documentation License, Prev: Tests, Up: Top + +Appendix D GNU Free Documentation License +***************************************** + + Version 1.3, 3 November 2008 + + Copyright (C) 2000, 2001, 2002, 2007, 2008 Free Software Foundation, Inc. + <http://fsf.org/> + + Everyone is permitted to copy and distribute verbatim copies + of this license document, but changing it is not allowed. + + 0. PREAMBLE + + The purpose of this License is to make a manual, textbook, or other + functional and useful document "free" in the sense of freedom: to + assure everyone the effective freedom to copy and redistribute it, + with or without modifying it, either commercially or + noncommercially. Secondarily, this License preserves for the + author and publisher a way to get credit for their work, while not + being considered responsible for modifications made by others. + + This License is a kind of "copyleft", which means that derivative + works of the document must themselves be free in the same sense. + It complements the GNU General Public License, which is a copyleft + license designed for free software. + + We have designed this License in order to use it for manuals for + free software, because free software needs free documentation: a + free program should come with manuals providing the same freedoms + that the software does. But this License is not limited to + software manuals; it can be used for any textual work, regardless + of subject matter or whether it is published as a printed book. We + recommend this License principally for works whose purpose is + instruction or reference. + + 1. APPLICABILITY AND DEFINITIONS + + This License applies to any manual or other work, in any medium, + that contains a notice placed by the copyright holder saying it can + be distributed under the terms of this License. Such a notice + grants a world-wide, royalty-free license, unlimited in duration, + to use that work under the conditions stated herein. The + "Document", below, refers to any such manual or work. Any member + of the public is a licensee, and is addressed as "you". You accept + the license if you copy, modify or distribute the work in a way + requiring permission under copyright law. + + A "Modified Version" of the Document means any work containing the + Document or a portion of it, either copied verbatim, or with + modifications and/or translated into another language. + + A "Secondary Section" is a named appendix or a front-matter section + of the Document that deals exclusively with the relationship of the + publishers or authors of the Document to the Document's overall + subject (or to related matters) and contains nothing that could + fall directly within that overall subject. (Thus, if the Document + is in part a textbook of mathematics, a Secondary Section may not + explain any mathematics.) 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For + works in formats which do not have any title page as such, "Title + Page" means the text near the most prominent appearance of the + work's title, preceding the beginning of the body of the text. + + The "publisher" means any person or entity that distributes copies + of the Document to the public. + + A section "Entitled XYZ" means a named subunit of the Document + whose title either is precisely XYZ or contains XYZ in parentheses + following text that translates XYZ in another language. (Here XYZ + stands for a specific section name mentioned below, such as + "Acknowledgements", "Dedications", "Endorsements", or "History".) + To "Preserve the Title" of such a section when you modify the + Document means that it remains a section "Entitled XYZ" according + to this definition. + + The Document may include Warranty Disclaimers next to the notice + which states that this License applies to the Document. 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In addition, you must do these things in + the Modified Version: + + A. Use in the Title Page (and on the covers, if any) a title + distinct from that of the Document, and from those of previous + versions (which should, if there were any, be listed in the + History section of the Document). You may use the same title + as a previous version if the original publisher of that + version gives permission. + + B. List on the Title Page, as authors, one or more persons or + entities responsible for authorship of the modifications in + the Modified Version, together with at least five of the + principal authors of the Document (all of its principal + authors, if it has fewer than five), unless they release you + from this requirement. + + C. State on the Title page the name of the publisher of the + Modified Version, as the publisher. + + D. Preserve all the copyright notices of the Document. + + E. Add an appropriate copyright notice for your modifications + adjacent to the other copyright notices. + + F. Include, immediately after the copyright notices, a license + notice giving the public permission to use the Modified + Version under the terms of this License, in the form shown in + the Addendum below. + + G. Preserve in that license notice the full lists of Invariant + Sections and required Cover Texts given in the Document's + license notice. + + H. Include an unaltered copy of this License. + + I. Preserve the section Entitled "History", Preserve its Title, + and add to it an item stating at least the title, year, new + authors, and publisher of the Modified Version as given on the + Title Page. If there is no section Entitled "History" in the + Document, create one stating the title, year, authors, and + publisher of the Document as given on its Title Page, then add + an item describing the Modified Version as stated in the + previous sentence. + + J. Preserve the network location, if any, given in the Document + for public access to a Transparent copy of the Document, and + likewise the network locations given in the Document for + previous versions it was based on. These may be placed in the + "History" section. You may omit a network location for a work + that was published at least four years before the Document + itself, or if the original publisher of the version it refers + to gives permission. + + K. For any section Entitled "Acknowledgements" or "Dedications", + Preserve the Title of the section, and preserve in the section + all the substance and tone of each of the contributor + acknowledgements and/or dedications given therein. + + L. Preserve all the Invariant Sections of the Document, unaltered + in their text and in their titles. Section numbers or the + equivalent are not considered part of the section titles. + + M. Delete any section Entitled "Endorsements". Such a section + may not be included in the Modified Version. + + N. Do not retitle any existing section to be Entitled + "Endorsements" or to conflict in title with any Invariant + Section. + + O. Preserve any Warranty Disclaimers. + + If the Modified Version includes new front-matter sections or + appendices that qualify as Secondary Sections and contain no + material copied from the Document, you may at your option designate + some or all of these sections as invariant. To do this, add their + titles to the list of Invariant Sections in the Modified Version's + license notice. These titles must be distinct from any other + section titles. + + You may add a section Entitled "Endorsements", provided it contains + nothing but endorsements of your Modified Version by various + parties--for example, statements of peer review or that the text + has been approved by an organization as the authoritative + definition of a standard. + + You may add a passage of up to five words as a Front-Cover Text, + and a passage of up to 25 words as a Back-Cover Text, to the end of + the list of Cover Texts in the Modified Version. Only one passage + of Front-Cover Text and one of Back-Cover Text may be added by (or + through arrangements made by) any one entity. If the Document + already includes a cover text for the same cover, previously added + by you or by arrangement made by the same entity you are acting on + behalf of, you may not add another; but you may replace the old + one, on explicit permission from the previous publisher that added + the old one. + + The author(s) and publisher(s) of the Document do not by this + License give permission to use their names for publicity for or to + assert or imply endorsement of any Modified Version. + + 5. COMBINING DOCUMENTS + + You may combine the Document with other documents released under + this License, under the terms defined in section 4 above for + modified versions, provided that you include in the combination all + of the Invariant Sections of all of the original documents, + unmodified, and list them all as Invariant Sections of your + combined work in its license notice, and that you preserve all + their Warranty Disclaimers. + + The combined work need only contain one copy of this License, and + multiple identical Invariant Sections may be replaced with a single + copy. If there are multiple Invariant Sections with the same name + but different contents, make the title of each such section unique + by adding at the end of it, in parentheses, the name of the + original author or publisher of that section if known, or else a + unique number. Make the same adjustment to the section titles in + the list of Invariant Sections in the license notice of the + combined work. + + In the combination, you must combine any sections Entitled + "History" in the various original documents, forming one section + Entitled "History"; likewise combine any sections Entitled + "Acknowledgements", and any sections Entitled "Dedications". You + must delete all sections Entitled "Endorsements." + + 6. COLLECTIONS OF DOCUMENTS + + You may make a collection consisting of the Document and other + documents released under this License, and replace the individual + copies of this License in the various documents with a single copy + that is included in the collection, provided that you follow the + rules of this License for verbatim copying of each of the documents + in all other respects. + + You may extract a single document from such a collection, and + distribute it individually under this License, provided you insert + a copy of this License into the extracted document, and follow this + License in all other respects regarding verbatim copying of that + document. + + 7. AGGREGATION WITH INDEPENDENT WORKS + + A compilation of the Document or its derivatives with other + separate and independent documents or works, in or on a volume of a + storage or distribution medium, is called an "aggregate" if the + copyright resulting from the compilation is not used to limit the + legal rights of the compilation's users beyond what the individual + works permit. When the Document is included in an aggregate, this + License does not apply to the other works in the aggregate which + are not themselves derivative works of the Document. + + If the Cover Text requirement of section 3 is applicable to these + copies of the Document, then if the Document is less than one half + of the entire aggregate, the Document's Cover Texts may be placed + on covers that bracket the Document within the aggregate, or the + electronic equivalent of covers if the Document is in electronic + form. Otherwise they must appear on printed covers that bracket + the whole aggregate. + + 8. TRANSLATION + + Translation is considered a kind of modification, so you may + distribute translations of the Document under the terms of section + 4. Replacing Invariant Sections with translations requires special + permission from their copyright holders, but you may include + translations of some or all Invariant Sections in addition to the + original versions of these Invariant Sections. You may include a + translation of this License, and all the license notices in the + Document, and any Warranty Disclaimers, provided that you also + include the original English version of this License and the + original versions of those notices and disclaimers. In case of a + disagreement between the translation and the original version of + this License or a notice or disclaimer, the original version will + prevail. + + If a section in the Document is Entitled "Acknowledgements", + "Dedications", or "History", the requirement (section 4) to + Preserve its Title (section 1) will typically require changing the + actual title. + + 9. TERMINATION + + You may not copy, modify, sublicense, or distribute the Document + except as expressly provided under this License. Any attempt + otherwise to copy, modify, sublicense, or distribute it is void, + and will automatically terminate your rights under this License. + + However, if you cease all violation of this License, then your + license from a particular copyright holder is reinstated (a) + provisionally, unless and until the copyright holder explicitly and + finally terminates your license, and (b) permanently, if the + copyright holder fails to notify you of the violation by some + reasonable means prior to 60 days after the cessation. + + Moreover, your license from a particular copyright holder is + reinstated permanently if the copyright holder notifies you of the + violation by some reasonable means, this is the first time you have + received notice of violation of this License (for any work) from + that copyright holder, and you cure the violation prior to 30 days + after your receipt of the notice. + + Termination of your rights under this section does not terminate + the licenses of parties who have received copies or rights from you + under this License. If your rights have been terminated and not + permanently reinstated, receipt of a copy of some or all of the + same material does not give you any rights to use it. + + 10. FUTURE REVISIONS OF THIS LICENSE + + The Free Software Foundation may publish new, revised versions of + the GNU Free Documentation License from time to time. Such new + versions will be similar in spirit to the present version, but may + differ in detail to address new problems or concerns. See + <http://www.gnu.org/copyleft/>. + + Each version of the License is given a distinguishing version + number. If the Document specifies that a particular numbered + version of this License "or any later version" applies to it, you + have the option of following the terms and conditions either of + that specified version or of any later version that has been + published (not as a draft) by the Free Software Foundation. If the + Document does not specify a version number of this License, you may + choose any version ever published (not as a draft) by the Free + Software Foundation. If the Document specifies that a proxy can + decide which future versions of this License can be used, that + proxy's public statement of acceptance of a version permanently + authorizes you to choose that version for the Document. + + 11. RELICENSING + + "Massive Multiauthor Collaboration Site" (or "MMC Site") means any + World Wide Web server that publishes copyrightable works and also + provides prominent facilities for anybody to edit those works. A + public wiki that anybody can edit is an example of such a server. + A "Massive Multiauthor Collaboration" (or "MMC") contained in the + site means any set of copyrightable works thus published on the MMC + site. + + "CC-BY-SA" means the Creative Commons Attribution-Share Alike 3.0 + license published by Creative Commons Corporation, a not-for-profit + corporation with a principal place of business in San Francisco, + California, as well as future copyleft versions of that license + published by that same organization. + + "Incorporate" means to publish or republish a Document, in whole or + in part, as part of another Document. + + An MMC is "eligible for relicensing" if it is licensed under this + License, and if all works that were first published under this + License somewhere other than this MMC, and subsequently + incorporated in whole or in part into the MMC, (1) had no cover + texts or invariant sections, and (2) were thus incorporated prior + to November 1, 2008. + + The operator of an MMC Site may republish an MMC contained in the + site under CC-BY-SA on the same site at any time before August 1, + 2009, provided the MMC is eligible for relicensing. + +ADDENDUM: How to use this License for your documents +==================================================== + +To use this License in a document you have written, include a copy of +the License in the document and put the following copyright and license +notices just after the title page: + + Copyright (C) YEAR YOUR NAME. + Permission is granted to copy, distribute and/or modify this document + under the terms of the GNU Free Documentation License, Version 1.3 + or any later version published by the Free Software Foundation; + with no Invariant Sections, no Front-Cover Texts, and no Back-Cover + Texts. A copy of the license is included in the section entitled ``GNU + Free Documentation License''. + + If you have Invariant Sections, Front-Cover Texts and Back-Cover +Texts, replace the "with...Texts." line with this: + + with the Invariant Sections being LIST THEIR TITLES, with + the Front-Cover Texts being LIST, and with the Back-Cover Texts + being LIST. + + If you have Invariant Sections without Cover Texts, or some other +combination of the three, merge those two alternatives to suit the +situation. + + If your document contains nontrivial examples of program code, we +recommend releasing these examples in parallel under your choice of free +software license, such as the GNU General Public License, to permit +their use in free software. + + + +Tag Table: +Node: Top835 +Node: Overview1858 +Node: Disclaimer2705 +Node: Installation3201 +Node: How to Use4054 +Node: JavaScript Detection7296 +Node: Free Licenses Detection10704 +Node: Setting Your JavaScript Free16876 +Node: Installation Requirements23722 +Node: LibreJS Internals25879 +Node: Tests27042 +Node: GNU Free Documentation License31549 + +End Tag Table |