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4  <html xmlns="http://www.w3.org/1999/xhtml" xml:lang="en">  - GNU Project - Free Software Foundation</title>
   
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6  <body>  <meta http-equiv="Keywords" content="GNU, FSF, Free Software Foundation, Linux, Emacs, GCC, Unix, Free Software, Operating System, GNU Kernel, HURD, GNU HURD, Hurd" />
7    <meta http-equiv="Description" content="Since 1983, developing the free Unix style operating system GNU, so that computer users can have the freedom to share and improve the software they use." />
8    
9  <p><a href="#translations">Translations</a> of this page</p>  <!--#include virtual="/philosophy/po/free-sw.translist" -->
10    <!--#include virtual="/server/banner.html" -->
11    
12    <h2>What is free software?</h2>
13    <!--#include virtual="/licenses/fsf-licensing.html" -->
14    
15  <h3>The Free Software Definition</h3>  <h3>The Free Software Definition</h3>
16    
17    <blockquote>
18  <p>  <p>
19  <a href="/graphics/philosophicalgnu.html"><img src="/graphics/philosophical-gnu-sm.jpg" alt=" [image of a Philosophical Gnu] " width="160" height="200" /></a>  The free software definition presents the criteria for whether a
20    particular software program qualifies as free software.  From time to
21    time we revise this definition, to clarify it or to resolve questions
22    about subtle issues.  See the <a href="#History">History section</a>
23    below for a list of changes that affect the definition of free
24    software.
25  </p>  </p>
26    </blockquote>
27    
28  <p>  <p>
29  We maintain this free software definition to show clearly what must be  &ldquo;Free software&rdquo; means software that respects users'
30  true about a particular software program for it to be considered  freedom and community.  Roughly, it means that <b>the users have the
31  free software.</p>  freedom to run, copy, distribute, study, change and improve the
32    software</b>.  Thus, &ldquo;free software&rdquo; is a matter of
33    liberty, not price.  To understand the concept, you should think of
34    &ldquo;free&rdquo; as in &ldquo;free speech,&rdquo; not as in
35    &ldquo;free beer&rdquo;.  We sometimes call it &ldquo;libre
36    software&rdquo; to show we do not mean it is gratis.
37    </p>
38    
39  <p>  <p>
40  ``Free software'' is a matter of liberty, not price.  To understand the  We campaign for these freedoms because everyone deserves them.  With
41  concept, you should think of ``free'' as in ``free speech,'' not as in  these freedoms, the users (both individually and collectively) control
42  ``free beer.''</p>  the program and what it does for them.  When users don't control the
43    program, we call it a &ldquo;nonfree&rdquo; or
44    &ldquo;proprietary&rdquo; program.  The nonfree program controls the
45    users, and the developer controls the program; this makes the
46    program <a href="/philosophy/free-software-even-more-important.html">
47    an instrument of unjust power</a>.
48    </p>
49    
50  <p>  <p>
51  Free software is a matter of the users' freedom to run, copy,  A program is free software if the program's users have the
52  distribute, study, change and improve the software.  More precisely,  four essential freedoms:
53  it refers to four kinds of freedom, for the users of the software:</p>  </p>
54    
55  <ul>  <ul>
56    <li>The freedom to run the program, for any purpose (freedom 0).</li>    <li>The freedom to run the program as you wish,
57    <li>The freedom to study how the program works, and adapt it to your needs        for any purpose (freedom 0).</li>
58        (freedom 1).   Access to the source code is a precondition for this.</li>    <li>The freedom to study how the program works, and change it so it
59          does your computing as you wish (freedom 1). Access to the source
60          code is a precondition for this.
61      </li>
62    <li>The freedom to redistribute copies so you can help your neighbor    <li>The freedom to redistribute copies so you can help your neighbor
63        (freedom 2).</li>        (freedom 2).
64    <li>The freedom to improve the program, and release your improvements    </li>
65       to the public, so that the whole community benefits    <li>The freedom to distribute copies of your modified versions
66        (freedom 3).   Access to the source code is a precondition for this.</li>        to others (freedom 3).  By doing this you can give the whole
67          community a chance to benefit from your changes.
68          Access to the source code is a precondition for this.
69      </li>
70  </ul>  </ul>
71    
72  <p>  <p>
73  A program is free software if users have all of these freedoms.  A program is free software if it gives users adequately all of these
74  Thus, you should be free to redistribute copies, either with or  freedoms.  Otherwise, it is nonfree.  While we can distinguish various
75  without modifications, either gratis or charging a fee for  nonfree distribution schemes in terms of how far they fall short of
76  distribution, to <a href="#exportcontrol">anyone anywhere</a>.  Being  being free, we consider them all equally unethical.</p>
77  free to do these things means (among other things) that you do not  
78  have to ask or pay for permission.</p>  <p>In any given scenario, these freedoms must apply to whatever code
79    we plan to make use of, or lead others to make use of.  For instance,
80    consider a program A which automatically launches a program B to
81    handle some cases.  If we plan to distribute A as it stands, that
82    implies users will need B, so we need to judge whether both A and B
83    are free.  However, if we plan to modify A so that it doesn't use B,
84    only A needs to be free; we can ignore B.</p>
85    
86    <p>The rest of this page clarifies certain points about what makes
87    specific freedoms adequate or not.</p>
88    
89    <p>Freedom to distribute (freedoms 2 and 3) means you are free to
90    redistribute copies, either with or without modifications, either
91    gratis or charging a fee for distribution, to
92    <a href="#exportcontrol">anyone anywhere</a>.  Being free to do these
93    things means (among other things) that you do not have to ask or pay
94    for permission to do so.
95    </p>
96    
97  <p>  <p>
98  You should also have the freedom to make modifications and use them  You should also have the freedom to make modifications and use them
99  privately in your own work or play, without even mentioning that they  privately in your own work or play, without even mentioning that they
100  exist.  If you do publish your changes, you should not be required to  exist.  If you do publish your changes, you should not be required to
101  notify anyone in particular, or in any particular way.</p>  notify anyone in particular, or in any particular way.
102    </p>
103    
104  <p>  <p>
105  The freedom to use a program means the freedom for any kind of person  The freedom to run the program means the freedom for any kind of person
106  or organization to use it on any kind of computer system, for any kind  or organization to use it on any kind of computer system, for any kind of
107  of overall job, and without being required to communicate subsequently  overall job and purpose, without being required to communicate about it
108  with the developer or any other specific entity.</p>  with the developer or any other specific entity.  In this freedom, it is
109    the <em>user's</em> purpose that matters, not the <em>developer's</em>
110    purpose; you as a user are free to run the program for your purposes,
111    and if you distribute it to someone else, she is then free to run it
112    for her purposes, but you are not entitled to impose your purposes on her.
113    </p>
114    
115    <p>
116    The freedom to run the program as you wish means that you are not
117    forbidden or stopped from doing so.  It has nothing to do with what
118    functionality the program has, or whether it is useful for what you
119    want to do.</p>
120    
121  <p>  <p>
122  The freedom to redistribute copies must include binary or executable  The freedom to redistribute copies must include binary or executable
123  forms of the program, as well as source code, for both modified and  forms of the program, as well as source code, for both modified and
124  unmodified versions.  (Distributing programs in runnable form is  unmodified versions.  (Distributing programs in runnable form is necessary
125  necessary for conveniently installable free operating systems.)  It is  for conveniently installable free operating systems.)  It is OK if there
126  ok if there is no way to produce a binary or executable form for a  is no way to produce a binary or executable form for a certain program
127  certain program (since some languages don't support that feature), but  (since some languages don't support that feature), but you must have the
128  you must have the freedom to redistribute such forms should you find  freedom to redistribute such forms should you find or develop a way to
129  or develop a way to make them.</p>  make them.
130  <p>  </p>
131  In order for the freedoms to make changes, and to publish improved  
132  versions, to be meaningful, you must have access to the source code of  <p>
133  the program.  Therefore, accessibility of source code is a necessary  In order for freedoms 1 and 3 (the freedom to make changes and the
134  condition for free software.</p>  freedom to publish the changed versions) to be meaningful, you must have
135  <p>  access to the source code of the program.  Therefore, accessibility of
136  In order for these freedoms to be real, they must be irrevocable as  source code is a necessary condition for free software.  Obfuscated
137  long as you do nothing wrong; if the developer of the software has the  &ldquo;source code&rdquo; is not real source code and does not count
138  power to revoke the license, without your doing anything to give  as source code.
139  cause, the software is not free.</p>  </p>
140    
141    <p>
142    Freedom 1 includes the freedom to use your changed version in place of
143    the original.  If the program is delivered in a product designed to
144    run someone else's modified versions but refuse to run yours &mdash; a
145    practice known as &ldquo;tivoization&rdquo; or &ldquo;lockdown&rdquo;,
146    or (in its practitioners' perverse terminology) as &ldquo;secure
147    boot&rdquo; &mdash; freedom 1 becomes an empty pretense rather than a
148    practical reality.  These binaries are not free
149    software even if the source code they are compiled from is free.
150    </p>
151    
152    <p>
153    One important way to modify a program is by merging in available free
154    subroutines and modules.  If the program's license says that you
155    cannot merge in a suitably licensed existing module &mdash; for instance, if it
156    requires you to be the copyright holder of any code you add &mdash; then the
157    license is too restrictive to qualify as free.
158    </p>
159    
160    <p>
161    Freedom 3 includes the freedom to release your modified versions
162    as free software.  A free license may also permit other ways of
163    releasing them; in other words, it does not have to be
164    a <a href="/copyleft/copyleft.html">copyleft</a> license.  However, a
165    license that requires modified versions to be nonfree does not qualify
166    as a free license.
167    </p>
168    
169    <p>
170    In order for these freedoms to be real, they must be permanent and
171    irrevocable as long as you do nothing wrong; if the developer of the
172    software has the power to revoke the license, or retroactively add
173    restrictions to its terms, without your doing anything wrong to give
174    cause, the software is not free.
175    </p>
176    
177  <p>  <p>
178  However, certain kinds of rules about the manner of distributing free  However, certain kinds of rules about the manner of distributing free
179  software are acceptable, when they don't conflict with the central  software are acceptable, when they don't conflict with the central
180  freedoms.  For example, copyleft (very simply stated) is the rule that  freedoms.  For example, <a href="/copyleft/copyleft.html">copyleft</a>
181  when redistributing the program, you cannot add restrictions to deny  (very simply stated) is the rule that when redistributing the program,
182  other people the central freedoms.  This rule does not conflict with  you cannot add restrictions to deny other people the central freedoms.
183  the central freedoms; rather it protects them.</p>  This rule does not conflict with the central freedoms; rather it
184  <p>  protects them.
185  You may have paid money to get copies of free software, or you  </p>
186  may have obtained copies at no charge.  But regardless of how you got  
 your copies, you always have the freedom to copy and change the  
 software, even to <a href="/philosophy/selling.html">sell copies</a>.</p>  
 <p>  
 ``Free software'' does not mean ``non-commercial''.  A free program  
 must be available for commercial use, commercial development, and  
 commercial distribution.  Commercial development of free software is  
 no longer unusual; such free commercial software is very important.</p>  
 <p>  
 Rules about how to package a modified version are acceptable, if they  
 don't substantively block your freedom to release modified versions.  
 Rules that ``if you make the program available in this way, you must  
 make it available in that way also'' can be acceptable too, on the  
 same condition.  (Note that such a rule still leaves you the choice of  
 whether to publish the program or not.)  It is also acceptable for the  
 license to require that, if you have distributed a modified version  
 and a previous developer asks for a copy of it, you must send one,  
 or that you identify yourself on your modifications.</p>  
 <p>  
 In the GNU project, we use <a href="/copyleft/copyleft.html">``copyleft''</a>  
 to protect these freedoms legally for everyone.  But  
 <a href="/philosophy/categories.html#Non-CopyleftedFreeSoftware">non-copylefted  
 free software</a> also exists.  We believe there are  
 important reasons why <a href="/philosophy/pragmatic.html"> it is  
 better to use copyleft</a>, but if your program is non-copylefted free  
 software, we can still use it.</p>  
 <p>  
 See <a href="/philosophy/categories.html">Categories of Free Software</a>  
 for a description of how ``free software,'' ``copylefted software'' and  
 other categories of software relate to each other.</p>  
 <p>  
 Sometimes government <a id="exportcontrol">export control  
 regulations</a> and trade sanctions can constrain your freedom to  
 distribute copies of programs internationally.  Software developers do  
 not have the power to eliminate or override these restrictions, but  
 what they can and must do is refuse to impose them as conditions of  
 use of the program.  In this way, the restrictions will not affect  
 activities and people outside the jurisdictions of these governments.</p>  
 <p>  
 Most free software licenses are based on copyright, and there are  
 limits on what kinds of requirements can be imposed through copyright.  
 If a copyright-based license respects freedom in the ways described  
 above, it is unlikely to have some other sort of problem that we never  
 anticipated (though this does happen occasionally).  However, some  
 free software licenses are based on contracts, and contracts can  
 impose a much larger range of possible restrictions.  That means there  
 are many possible ways such a license could be unacceptably  
 restrictive and non-free.</p>  
 <p>  
 We can't possibly list all the possible contract restrictions that  
 would be unacceptable.  If a contract-based license restricts the user  
 in an unusual way that copyright-based licenses cannot, and which  
 isn't mentioned here as legitimate, we will have to think about it,  
 and we will probably decide it is non-free.</p>  
 <p>  
 When talking about free software, it is best to avoid using terms like  
 ``give away'' or ``for free'', because those terms imply that the  
 issue is about price, not freedom.  Some common terms such as  
 ``piracy'' embody opinions we hope you won't endorse.  See  
 <a href="/philosophy/words-to-avoid.html">Confusing Words and Phrases  
 that are Worth Avoiding</a> for a discussion of these terms.  
 We also have a list of <a href="/philosophy/fs-translations.html">translations  
 of "free software"</a> into various languages.</p>  
187  <p>  <p>
188  Finally, note that criteria such as those stated in this free software  In the GNU project, we use copyleft to protect the four freedoms
189  definition require careful thought for their interpretation.  To  legally for everyone.  We believe there are important reasons why
190  decide whether a specific software license qualifies as a free  <a href="/philosophy/pragmatic.html">it is better to use
191  software license, we judge it based on these criteria to determine  copyleft</a>.  However,
192  whether it fits their spirit as well as the precise words.  If a  <a href="/philosophy/categories.html#Non-CopyleftedFreeSoftware">
193  license includes unconscionable restrictions, we reject it, even if we  noncopylefted free software</a> is ethical
194  did not anticipate the issue in these criteria.  Sometimes a license  too.  See <a href="/philosophy/categories.html">Categories of Free
195  requirement raises an issue that calls for extensive thought,  Software</a> for a description of how &ldquo;free software,&rdquo;
196  including discussions with a lawyer, before we can decide if the  &ldquo;copylefted software&rdquo; and other categories of software
197  requirement is acceptable.  When we reach a conclusion about a new  relate to each other.
 issue, we often update these criteria to make it easier to see why  
 certain licenses do or don't qualify.</p>  
 <p>  
 If you are interested in whether a specific license qualifies as a  
 free software license, see our <a  
 href="/licenses/license-list.html">list of licenses</a>.  If the  
 license you are concerned with is not listed there, you can ask us  
 about it by sending us email at <a  
 href="mailto:licensing@gnu.org">&lt;licensing@gnu.org&gt;</a>.</p> <p>  
 If you are contemplating writing a new license, please contact the FSF  
 by writing to that address. The proliferation of different free  
 software licenses means increased work for users in understanding the  
 licenses; we may be able to help you find an existing Free Software  
 license that meets your needs.  
198  </p>  </p>
199    
200  <p>  <p>
201  If that isn't possible, if you really need a new license, with our  &ldquo;Free software&rdquo; does not mean &ldquo;noncommercial&rdquo;.  A free
202  help you can ensure that the license really is a Free Software license  program must be available for commercial use, commercial development,
203  and avoid various practical problems.  and commercial distribution.  Commercial development of free software
204    is no longer unusual; such free commercial software is very important.
205    You may have paid money to get copies of free software, or you may have
206    obtained copies at no charge.  But regardless of how you got your copies,
207    you always have the freedom to copy and change the software, even to
208    <a href="/philosophy/selling.html">sell copies</a>.
209  </p>  </p>
 <hr />  
210    
211  <p>  <p>
212  Another group has started using the term "open source" to mean  Whether a change constitutes an improvement is a subjective matter.
213  something close (but not identical) to "free software".  We prefer the  If your right to modify a program is limited, in substance, to changes that
214  term "free software" because, once you have heard it refers to freedom  someone else considers an improvement, that program is not free.
215  rather than price, <a href="free-software-for-freedom.html">it calls  </p>
216  to mind freedom</a>.  The word "open" never does that.</p>  
217    <p>
218  <hr />  However, rules about how to package a modified version are acceptable,
219  <h4><a href="/philosophy/philosophy.html">Other Texts to Read</a></h4>  if they don't substantively limit your freedom to release modified
220    versions, or your freedom to make and use modified versions privately.
221    Thus, it is acceptable for the license to require that you change the
222  <!-- All pages on the GNU web server should have the section about    -->  name of the modified version, remove a logo, or identify your
223  <!-- verbatim copying.  Please do NOT remove this without talking     -->  modifications as yours.  As long as these requirements are not so
224  <!-- with the webmasters first. -->  burdensome that they effectively hamper you from releasing your
225  <!-- Please make sure the copyright date is consistent with the document -->  changes, they are acceptable; you're already making other changes to
226  <!-- and that it is like this "2001, 2002" not this "2001-2002." -->  the program, so you won't have trouble making a few more.
227    </p>
228  <div class="translations">  
229  <p><a id="translations"></a>  <p>
230  <b>Translations of this page</b>:<br />  Rules that &ldquo;if you make your version available in this way, you
231    must make it available in that way also&rdquo; can be acceptable too,
232  <!-- Please keep this list alphabetical, and in the original -->  on the same condition.  An example of such an acceptable rule is one
233  <!-- language if possible, otherwise default to English -->  saying that if you have distributed a
234  <!-- If you do not have it English, please comment what the -->  modified version and a previous developer asks for a copy of it, you
235  <!-- English is.  If you add a new language here, please -->  must send one.  (Note that such a rule still leaves you the choice of
236  <!-- advise web-translators@gnu.org and add it to -->  whether to distribute your version at all.)  Rules that require release
237  <!--    - in /home/www/bin/nightly-vars either TAGSLANG or WEBLANG -->  of source code to the users for versions that you put into public use
238  <!--    - in /home/www/html/server/standards/README.translations.html -->  are also acceptable.
239  <!--      one of the lists under the section "Translations Underway" -->  </p>
240  <!--    - if there is a translation team, you also have to add an alias -->  
241  <!--      to mail.gnu.org:/com/mailer/aliases -->  <p>
242  <!-- Please also check you have the 2 letter language code right versus -->  A special issue arises when a license requires changing the name by
243  <!--     http://www.w3.org/WAI/ER/IG/ert/iso639.htm -->  which the program will be invoked from other programs.  That
244  [  effectively hampers you from releasing your changed version so that it
245    <a href="/philosophy/free-sw.ca.html">Catal&#x00e0;</a>       <!-- Catalan -->  can replace the original when invoked by those other programs.  This
246    sort of requirement is acceptable only if there's a suitable aliasing
247  <!-- Chinese (Simplified) -->  facility that allows you to specify the original program's name as an
248  | <a href="/philosophy/free-sw.cn.html">&#x7b80;&#x4f53;&#x4e2d;&#x6587;</a>  alias for the modified version.</p>
249    
250  <!-- Chinese (Traditional) -->  <p>
251  | <a href="/philosophy/free-sw.zh.html">&#x7e41;&#x9ad4;&#x4e2d;&#x6587;</a>  Sometimes government <a id="exportcontrol">export control regulations</a>
252    and trade sanctions can constrain your freedom to distribute copies of
253  | <a href="/philosophy/free-sw.cs.html">&#x010c;esky</a>        <!-- Czech -->  programs internationally.  Software developers do not have the power to
254  | <a href="/philosophy/free-sw.da.html">Dansk</a>       <!-- Danish -->  eliminate or override these restrictions, but what they can and must do
255  | <a href="/philosophy/free-sw.de.html">Deutsch</a>     <!-- German -->  is refuse to impose them as conditions of use of the program.  In this
256  | <a href="/philosophy/free-sw.html">English</a>  way, the restrictions will not affect activities and people outside the
257  | <a href="/philosophy/free-sw.es.html">Espa&#x00f1;ol</a>      <!-- Spanish -->  jurisdictions of these governments.  Thus, free software licenses
258    must not require obedience to any nontrivial export regulations as a
259  <!-- Persian/Farsi -->  condition of exercising any of the essential freedoms.
260  | <a href="/philosophy/free-sw.fa.html">&#x0641;&#x0627;&#x0631;&#x0633;&#x06cc;</a>  </p>
261    
262  | <a href="/philosophy/free-sw.fr.html">Fran&#x00e7;ais</a>     <!-- French -->  <p>
263  | <a href="/philosophy/free-sw.gl.html">Galego</a>      <!-- Galician -->  Merely mentioning the existence of export regulations, without making
264  | <a href="/philosophy/free-sw.he.html">&#x05e2;&#x05d1;&#x05e8;&#x05d9;&#x05ea;</a>    <!-- Hebrew -->  them a condition of the license itself, is acceptable since it does
265  | <a href="/philosophy/free-sw.hr.html">Hrvatski</a>    <!-- Croatian -->  not restrict users.  If an export regulation is actually trivial for
266  | <a href="/philosophy/free-sw.id.html">Bahasa Indonesia</a>    <!-- Indonesian -->  free software, then requiring it as a condition is not an actual
267  | <a href="/philosophy/free-sw.it.html">Italiano</a>    <!-- Italian -->  problem; however, it is a potential problem, since a later change in
268  | <a href="/philosophy/free-sw.ja.html">&#x65e5;&#x672c;&#x8a9e;</a>    <!-- Japanese -->  export law could make the requirement nontrivial and thus render the
269  | <a href="/philosophy/free-sw.ko.html">&#xd55c;&#xad6d;&#xc5b4;</a>    <!-- Korean -->  software nonfree.
270  | <a href="/philosophy/free-sw.hu.html">Magyar</a>      <!-- Hungarian -->  </p>
271  | <a href="/philosophy/free-sw.nl.html">Nederlands</a>  <!-- Dutch -->  
272  | <a href="/philosophy/free-sw.no.html">Norsk</a>       <!-- Norwegian -->  <p>
273  | <a href="/philosophy/free-sw.pl.html">Polski</a>      <!-- Polish -->  A free license may not require compliance with the license of a
274  | <a href="/philosophy/free-sw.pt.html">Portugu&#x0ea;s</a>     <!-- Portuguese -->  nonfree program.  Thus, for instance, if a license requires you to
275  | <a href="/philosophy/free-sw.ro.html">Rom&#x00e2;n&#x0103;</a>        <!-- Romanian -->  comply with the licenses of &ldquo;all the programs you use&rdquo;, in
276  | <a href="/philosophy/free-sw.ru.html">&#1056;&#1091;&#1089;&#1089;&#1082;&#1080;&#1081;</a> <!-- Russian -->  the case of a user that runs nonfree programs this would require
277  | <a href="/philosophy/free-sw.sl.html">Slovinsko</a>   <!--- Slovenian -->  compliance with the licenses of those nonfree programs; that makes the
278  | <a href="/philosophy/free-sw.sr.html">&#x0421;&#x0440;&#x043f;&#x0441;&#x043a;&#x0438;</a> <!-- Serbian -->  license nonfree.
279  | <a href="/philosophy/free-sw.tr.html">T&#x00fc;rk&#x00e7;e</a>        <!-- Turkish -->  </p>
280  ]  
281    <p>
282    It is acceptable for a free license to specify which jurisdiction's
283    law applies, or where litigation must be done, or both.
284  </p>  </p>
 </div>  
285    
 <div class="copyright">  
286  <p>  <p>
287  Return to the <a href="/home.html">GNU Project home page</a>.  Most free software licenses are based on copyright, and there are limits
288    on what kinds of requirements can be imposed through copyright.  If a
289    copyright-based license respects freedom in the ways described above, it
290    is unlikely to have some other sort of problem that we never anticipated
291    (though this does happen occasionally).  However, some free software
292    licenses are based on contracts, and contracts can impose a much larger
293    range of possible restrictions.  That means there are many possible ways
294    such a license could be unacceptably restrictive and nonfree.
295  </p>  </p>
296    
297  <p>  <p>
298  Please send FSF &amp; GNU inquiries to  We can't possibly list all the ways that might happen.  If a
299  <a href="mailto:gnu@gnu.org"><em>gnu@gnu.org</em></a>.  contract-based license restricts the user in an unusual way that
300  There are also <a href="/home.html#ContactInfo">other ways to contact</a>  copyright-based licenses cannot, and which isn't mentioned here as
301  the FSF.  legitimate, we will have to think about it, and we will probably conclude
302  <br />  it is nonfree.
 Please send broken links and other corrections (or suggestions) to  
 <a href="mailto:webmasters@gnu.org"><em>webmasters@gnu.org</em></a>.  
303  </p>  </p>
304    
305  <p>  <p>
306  Please see the  When talking about free software, it is best to avoid using terms
307  <a href="/server/standards/README.translations.html">Translations  like &ldquo;give away&rdquo; or &ldquo;for free,&rdquo; because those terms imply that
308  README</a> for information on coordinating and submitting  the issue is about price, not freedom.  Some common terms such
309  translations of this article.  as &ldquo;piracy&rdquo; embody opinions we hope you won't endorse.  See
310    <a href="/philosophy/words-to-avoid.html">Confusing Words and Phrases that
311    are Worth Avoiding</a> for a discussion of these terms.  We also have
312    a list of proper <a href="/philosophy/fs-translations.html">translations of
313    &ldquo;free software&rdquo;</a> into various languages.
314    </p>
315    
316    <p>
317    Finally, note that criteria such as those stated in this free software
318    definition require careful thought for their interpretation.  To decide
319    whether a specific software license qualifies as a free software license,
320    we judge it based on these criteria to determine whether it fits their
321    spirit as well as the precise words.  If a license includes unconscionable
322    restrictions, we reject it, even if we did not anticipate the issue
323    in these criteria.  Sometimes a license requirement raises an issue
324    that calls for extensive thought, including discussions with a lawyer,
325    before we can decide if the requirement is acceptable.  When we reach
326    a conclusion about a new issue, we often update these criteria to make
327    it easier to see why certain licenses do or don't qualify.
328    </p>
329    
330    <p>
331    If you are interested in whether a specific license qualifies as a free
332    software license, see our <a href="/licenses/license-list.html">list
333    of licenses</a>.  If the license you are concerned with is not
334    listed there, you can ask us about it by sending us email at
335    <a href="mailto:licensing@gnu.org">&lt;licensing@gnu.org&gt;</a>.
336    </p>
337    
338    <p>
339    If you are contemplating writing a new license, please contact the
340    Free Software Foundation first by writing to that address. The
341    proliferation of different free software licenses means increased work
342    for users in understanding the licenses; we may be able to help you
343    find an existing free software license that meets your needs.
344    </p>
345    
346    <p>
347    If that isn't possible, if you really need a new license, with our
348    help you can ensure that the license really is a free software license
349    and avoid various practical problems.
350    </p>
351    
352    <h3 id="beyond-software">Beyond Software</h3>
353    
354    <p>
355    <a href="/philosophy/free-doc.html">Software manuals must be free</a>,
356    for the same reasons that software must be free, and because the
357    manuals are in effect part of the software.
358  </p>  </p>
359    
360  <p>  <p>
361  Copyright (C) 1996, 1997, 1998, 1999, 2000, 2001, 2002, 2003, 2004 Free  The same arguments also make sense for other kinds of works of
362  Software Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  practical use &mdash; that is to say, works that embody useful knowledge,
363  02110,  USA  such as educational works and reference
364  <br />  works.  <a href="http://wikipedia.org">Wikipedia</a> is the best-known
365  Verbatim copying and distribution of this entire article is  example.
 permitted in any medium without royalty provided this notice is  
 preserved.  
366  </p>  </p>
367    
368  <p>  <p>
369  Updated:  Any kind of work <em>can</em> be free, and the definition of free software
370    has been extended to a definition of <a href="http://freedomdefined.org/">
371    free cultural works</a> applicable to any kind of works.
372    </p>
373    
374    <h3 id="open-source">Open Source?</h3>
375    
376    <p>
377    Another group has started using the term &ldquo;open source&rdquo; to mean
378    something close (but not identical) to &ldquo;free software&rdquo;.  We
379    prefer the term &ldquo;free software&rdquo; because, once you have heard that
380    it refers to freedom rather than price, it calls to mind freedom.  The
381    word &ldquo;open&rdquo; <a href="/philosophy/open-source-misses-the-point.html">
382    never refers to freedom</a>.
383    </p>
384    
385    <h3 id="History">History</h3>
386    
387    <p>From time to time we revise this Free Software Definition.  Here is
388    the list of substantive changes, along with links to show exactly what
389    was changed.</p>
390    
391    <ul>
392    
393    <li><a href="http://web.cvs.savannah.gnu.org/viewvc/www/philosophy/free-sw.html?root=www&amp;r1=1.140&amp;r2=1.141">Version
394    1.141</a>: Clarify which code needs to be free.</li>
395    
396    <li><a href="http://web.cvs.savannah.gnu.org/viewvc/www/philosophy/free-sw.html?root=www&amp;r1=1.134&amp;r2=1.135">Version
397    1.135</a>: Say each time that freedom 0 is the freedom to run the program
398    as you wish.</li>
399    
400    <li><a href="http://web.cvs.savannah.gnu.org/viewvc/www/philosophy/free-sw.html?root=www&amp;r1=1.133&amp;r2=1.134">Version
401    1.134</a>: Freedom 0 is not a matter of the program's functionality.</li>
402    
403    <li><a href="http://web.cvs.savannah.gnu.org/viewvc/www/philosophy/free-sw.html?root=www&amp;r1=1.130&amp;r2=1.131">Version
404    1.131</a>: A free license may not require compliance with a nonfree license
405    of another program.</li>
406    
407    <li><a href="http://web.cvs.savannah.gnu.org/viewvc/www/philosophy/free-sw.html?root=www&amp;r1=1.128&amp;r2=1.129">Version
408    1.129</a>: State explicitly that choice of law and choice of forum
409    specifications are allowed.  (This was always our policy.)</li>
410    
411    <li><a href="http://web.cvs.savannah.gnu.org/viewvc/www/philosophy/free-sw.html?root=www&amp;r1=1.121&amp;r2=1.122">Version
412    1.122</a>: An export control requirement is a real problem if the
413    requirement is nontrivial; otherwise it is only a potential problem.</li>
414    
415    <li><a href="http://web.cvs.savannah.gnu.org/viewvc/www/philosophy/free-sw.html?root=www&amp;r1=1.117&amp;r2=1.118">Version
416    1.118</a>: Clarification: the issue is limits on your right to modify,
417    not on what modifications you have made.  And modifications are not limited
418    to &ldquo;improvements&rdquo;</li>
419    
420    <li><a href="http://web.cvs.savannah.gnu.org/viewvc/www/philosophy/free-sw.html?root=www&amp;r1=1.110&amp;r2=1.111">Version
421    1.111</a>: Clarify 1.77 by saying that only
422    retroactive <em>restrictions</em> are unacceptable.  The copyright
423    holders can always grant additional <em>permission</em> for use of the
424    work by releasing the work in another way in parallel.</li>
425    
426    <li><a href="http://web.cvs.savannah.gnu.org/viewvc/www/philosophy/free-sw.html?root=www&amp;r1=1.104&amp;r2=1.105">Version
427    1.105</a>: Reflect, in the brief statement of freedom 1, the point
428    (already stated in version 1.80) that it includes really using your modified
429    version for your computing.</li>
430    
431    <li><a href="http://web.cvs.savannah.gnu.org/viewvc/www/philosophy/free-sw.html?root=www&amp;r1=1.91&amp;r2=1.92">Version
432    1.92</a>: Clarify that obfuscated code does not qualify as source code.</li>
433    
434    <li><a href="http://web.cvs.savannah.gnu.org/viewvc/www/philosophy/free-sw.html?root=www&amp;r1=1.89&amp;r2=1.90">Version
435    1.90</a>: Clarify that freedom 3 means the right to distribute copies
436    of your own modified or improved version, not a right to participate
437    in someone else's development project.</li>
438    
439    <li><a href="http://web.cvs.savannah.gnu.org/viewvc/www/philosophy/free-sw.html?root=www&amp;r1=1.88&amp;r2=1.89">Version
440    1.89</a>: Freedom 3 includes the right to release modified versions as
441    free software.</li>
442    
443    <li><a href="http://web.cvs.savannah.gnu.org/viewvc/www/philosophy/free-sw.html?root=www&amp;r1=1.79&amp;r2=1.80">Version
444    1.80</a>: Freedom 1 must be practical, not just theoretical;
445    i.e., no tivoization.</li>
446    
447    <li><a href="http://web.cvs.savannah.gnu.org/viewvc/www/philosophy/free-sw.html?root=www&amp;r1=1.76&amp;r2=1.77">Version
448    1.77</a>: Clarify that all retroactive changes to the license are
449    unacceptable, even if it's not described as a complete
450    replacement.</li>
451    
452    <li><a href="http://web.cvs.savannah.gnu.org/viewvc/www/philosophy/free-sw.html?root=www&amp;r1=1.73&amp;r2=1.74">Version
453    1.74</a>: Four clarifications of points not explicit enough, or stated
454    in some places but not reflected everywhere:
455    <ul>
456    <li>"Improvements" does not mean the license can
457    substantively limit what kinds of modified versions you can release.
458    Freedom 3 includes distributing modified versions, not just changes.</li>
459    <li>The right to merge in existing modules
460    refers to those that are suitably licensed.</li>
461    <li>Explicitly state the conclusion of the point about export controls.</li>
462    <li>Imposing a license change constitutes revoking the old license.</li>
463    </ul>
464    </li>
465    
466    <li><a href="http://web.cvs.savannah.gnu.org/viewvc/www/philosophy/free-sw.html?root=www&amp;r1=1.56&amp;r2=1.57">Version
467    1.57</a>: Add &quot;Beyond Software&quot; section.</li>
468    
469    <li><a href="http://web.cvs.savannah.gnu.org/viewvc/www/philosophy/free-sw.html?root=www&amp;r1=1.45&amp;r2=1.46">Version
470    1.46</a>: Clarify whose purpose is significant in the freedom to run
471    the program for any purpose.</li>
472    
473    <li><a href="http://web.cvs.savannah.gnu.org/viewvc/www/philosophy/free-sw.html?root=www&amp;r1=1.40&amp;r2=1.41">Version
474    1.41</a>: Clarify wording about contract-based licenses.</li>
475    
476    <li><a href="http://web.cvs.savannah.gnu.org/viewvc/www/philosophy/free-sw.html?root=www&amp;r1=1.39&amp;r2=1.40">Version
477    1.40</a>: Explain that a free license must allow to you use other
478    available free software to create your modifications.</li>
479    
480    <li><a href="http://web.cvs.savannah.gnu.org/viewvc/www/philosophy/free-sw.html?root=www&amp;r1=1.38&amp;r2=1.39">Version
481    1.39</a>: Note that it is acceptable for a license to require you to
482    provide source for versions of the software you put into public
483    use.</li>
484    
485    <li><a href="http://web.cvs.savannah.gnu.org/viewvc/www/philosophy/free-sw.html?root=www&amp;r1=1.30&amp;r2=1.31">Version
486    1.31</a>: Note that it is acceptable for a license to require you to
487    identify yourself as the author of modifications.  Other minor
488    clarifications throughout the text.</li>
489    
490    <li><a href="http://web.cvs.savannah.gnu.org/viewvc/www/philosophy/free-sw.html?root=www&amp;r1=1.22&amp;r2=1.23">Version
491    1.23</a>: Address potential problems related to contract-based
492    licenses.</li>
493    
494    <li><a href="http://web.cvs.savannah.gnu.org/viewvc/www/philosophy/free-sw.html?root=www&amp;r1=1.15&amp;r2=1.16">Version
495    1.16</a>: Explain why distribution of binaries is important.</li>
496    
497    <li><a href="http://web.cvs.savannah.gnu.org/viewvc/www/philosophy/free-sw.html?root=www&amp;r1=1.10&amp;r2=1.11">Version
498    1.11</a>: Note that a free license may require you to send a copy of
499    versions you distribute to the author.</li>
500    
501    </ul>
502    
503    <p>There are gaps in the version numbers shown above because there are
504    other changes in this page that do not affect the definition or its
505    interpretations.  For instance, the list does not include changes in
506    asides, formatting, spelling, punctuation, or other parts of the page.
507    You can review the complete list of changes to the page through
508    the <a href="http://web.cvs.savannah.gnu.org/viewvc/www/philosophy/free-sw.html?root=www&amp;view=log">cvsweb
509    interface</a>.</p>
510    
511    
512    </div><!-- for id="content", starts in the include above -->
513    <!--#include virtual="/server/footer.html" -->
514    <div id="footer">
515    <div class="unprintable">
516    
517    <p>Please send general FSF &amp; GNU inquiries to
518    <a href="mailto:gnu@gnu.org">&lt;gnu@gnu.org&gt;</a>.
519    There are also <a href="/contact/">other ways to contact</a>
520    the FSF.  Broken links and other corrections or suggestions can be sent
521    to <a href="mailto:webmasters@gnu.org">&lt;webmasters@gnu.org&gt;</a>.</p>
522    
523    <p><!-- TRANSLATORS: Ignore the original text in this paragraph,
524            replace it with the translation of these two:
525    
526            We work hard and do our best to provide accurate, good quality
527            translations.  However, we are not exempt from imperfection.
528            Please send your comments and general suggestions in this regard
529            to <a href="mailto:web-translators@gnu.org">
530            &lt;web-translators@gnu.org&gt;</a>.</p>
531    
532            <p>For information on coordinating and submitting translations of
533            our web pages, see <a
534            href="/server/standards/README.translations.html">Translations
535            README</a>. -->
536    Please see the <a
537    href="/server/standards/README.translations.html">Translations
538    README</a> for information on coordinating and submitting translations
539    of this article.</p>
540    </div>
541    
542    <!-- Regarding copyright, in general, standalone pages (as opposed to
543         files generated as part of manuals) on the GNU web server should
544         be under CC BY-ND 3.0 US.  Please do NOT change or remove this
545         without talking with the webmasters or licensing team first.
546         Please make sure the copyright date is consistent with the
547         document.  For web pages, it is ok to list just the latest year the
548         document was modified, or published.
549        
550         If you wish to list earlier years, that is ok too.
551         Either "2001, 2002, 2003" or "2001-2003" are ok for specifying
552         years, as long as each year in the range is in fact a copyrightable
553         year, i.e., a year in which the document was published (including
554         being publicly visible on the web or in a revision control system).
555        
556         There is more detail about copyright years in the GNU Maintainers
557         Information document, www.gnu.org/prep/maintain. -->
558    
559    <p>Copyright &copy; 1996-2002, 2004-2007, 2009, 2010, 2012, 2013, 2015
560    Free Software Foundation, Inc.</p>
561    
562    <p>This page is licensed under a <a rel="license"
563    href="http://creativecommons.org/licenses/by-nd/3.0/us/">Creative
564    Commons Attribution-NoDerivs 3.0 United States License</a>.</p>
565    
566    <!--#include virtual="/server/bottom-notes.html" -->
567    
568    <p class="unprintable">Updated:
569  <!-- timestamp start -->  <!-- timestamp start -->
570  $Date$ $Author$  $Date$
571  <!-- timestamp end -->  <!-- timestamp end -->
572  </p>  </p>
573  </div>  </div>
574    </div>
575  </body>  </body>
576  </html>  </html>

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