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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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8    
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11    
12    <h2>What is free software?</h2>
13    
14  <h3>The Free Software Definition</h3>  <h3>The Free Software Definition</h3>
15    
16    <blockquote>
17  <p>  <p>
18  <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
19    particular software program qualifies as free software.  From time to
20    time we revise this definition, to clarify it or to resolve questions
21    about subtle issues.  See the <a href="#History">History section</a>
22    below for a list of changes that affect the definition of free
23    software.
24  </p>  </p>
25    </blockquote>
26    
27  <p>  <p>
28  We maintain this free software definition to show clearly what must be  &ldquo;Free software&rdquo; means software that respects users'
29  true about a particular software program for it to be considered  freedom and community.  Roughly, it means that <b>the users have the
30  free software.</p>  freedom to run, copy, distribute, study, change and improve the
31    software</b>.  Thus, &ldquo;free software&rdquo; is a matter of
32    liberty, not price.  To understand the concept, you should think of
33    &ldquo;free&rdquo; as in &ldquo;free speech,&rdquo; not as in
34    &ldquo;free beer&rdquo;.
35    </p>
36    
37  <p>  <p>
38  ``Free software'' is a matter of liberty, not price.  To understand the  We campaign for these freedoms because everyone deserves them.  With
39  concept, you should think of ``free'' as in ``free speech,'' not as in  these freedoms, the users (both individually and collectively) control
40  ``free beer.''</p>  the program and what it does for them.  When users don't control the
41    program, we call it a &ldquo;nonfree&rdquo; or
42    &ldquo;proprietary&rdquo; program.  The nonfree program controls the
43    users, and the developer controls the program; this makes the
44    program <a href="/philosophy/free-software-even-more-important.html">
45    an instrument of unjust power</a>.
46    </p>
47    
48  <p>  <p>
49  Free software is a matter of the users' freedom to run, copy,  A program is free software if the program's users have the
50  distribute, study, change and improve the software.  More precisely,  four essential freedoms:
51  it refers to four kinds of freedom, for the users of the software:</p>  </p>
52    
53  <ul>  <ul>
54    <li>The freedom to run the program, for any purpose (freedom 0).</li>    <li>The freedom to run the program, for any purpose (freedom 0).</li>
55    <li>The freedom to study how the program works, and adapt it to your needs    <li>The freedom to study how the program works, and change it so it
56        (freedom 1).   Access to the source code is a precondition for this.</li>        does your computing as you wish (freedom 1). Access to the source
57          code is a precondition for this.
58      </li>
59    <li>The freedom to redistribute copies so you can help your neighbor    <li>The freedom to redistribute copies so you can help your neighbor
60        (freedom 2).</li>        (freedom 2).
61    <li>The freedom to improve the program, and release your improvements    </li>
62       to the public, so that the whole community benefits    <li>The freedom to distribute copies of your modified versions
63        (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
64          community a chance to benefit from your changes.
65          Access to the source code is a precondition for this.
66      </li>
67  </ul>  </ul>
68    
69  <p>  <p>
70  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
71  Thus, you should be free to redistribute copies, either with or  freedoms.  Otherwise, it is nonfree.  While we can distinguish various
72  without modifications, either gratis or charging a fee for  nonfree distribution schemes in terms of how far they fall short of
73  distribution, to <a href="#exportcontrol">anyone anywhere</a>.  Being  being free, we consider them all equally unethical.</p>
74  free to do these things means (among other things) that you do not  
75  have to ask or pay for permission.</p>  <p>The rest of this page clarifies certain points about what makes
76    specific freedoms adequate or not.</p>
77    
78    <p>Freedom to distribute (freedoms 2 and 3) means you are free to
79    redistribute copies, either with or without modifications, either
80    gratis or charging a fee for distribution, to
81    <a href="#exportcontrol">anyone anywhere</a>.  Being free to do these
82    things means (among other things) that you do not have to ask or pay
83    for permission to do so.
84    </p>
85    
86  <p>  <p>
87  You should also have the freedom to make modifications and use them  You should also have the freedom to make modifications and use them
88  privately in your own work or play, without even mentioning that they  privately in your own work or play, without even mentioning that they
89  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
90  notify anyone in particular, or in any particular way.</p>  notify anyone in particular, or in any particular way.
91    </p>
92    
93  <p>  <p>
94  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
95  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
96  of overall job, and without being required to communicate subsequently  overall job and purpose, without being required to communicate about it
97  with the developer or any other specific entity.</p>  with the developer or any other specific entity.  In this freedom, it is
98    the <em>user's</em> purpose that matters, not the <em>developer's</em>
99    purpose; you as a user are free to run the program for your purposes,
100    and if you distribute it to someone else, she is then free to run it
101    for her purposes, but you are not entitled to impose your purposes on her.
102    </p>
103    
104  <p>  <p>
105  The freedom to redistribute copies must include binary or executable  The freedom to redistribute copies must include binary or executable
106  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
107  unmodified versions.  (Distributing programs in runnable form is  unmodified versions.  (Distributing programs in runnable form is necessary
108  necessary for conveniently installable free operating systems.)  It is  for conveniently installable free operating systems.)  It is OK if there
109  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
110  certain program (since some languages don't support that feature), but  (since some languages don't support that feature), but you must have the
111  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
112  or develop a way to make them.</p>  make them.
113  <p>  </p>
114  In order for the freedoms to make changes, and to publish improved  
115  versions, to be meaningful, you must have access to the source code of  <p>
116  the program.  Therefore, accessibility of source code is a necessary  In order for freedoms 1 and 3 (the freedom to make changes and the
117  condition for free software.</p>  freedom to publish the changed versions) to be meaningful, you must have
118  <p>  access to the source code of the program.  Therefore, accessibility of
119  In order for these freedoms to be real, they must be irrevocable as  source code is a necessary condition for free software.  Obfuscated
120  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
121  power to revoke the license, without your doing anything to give  as source code.
122  cause, the software is not free.</p>  </p>
123    
124    <p>
125    Freedom 1 includes the freedom to use your changed version in place of
126    the original.  If the program is delivered in a product designed to
127    run someone else's modified versions but refuse to run yours &mdash; a
128    practice known as &ldquo;tivoization&rdquo; or &ldquo;lockdown&rdquo;,
129    or (in its practitioners' perverse terminology) as &ldquo;secure
130    boot&rdquo; &mdash; freedom 1 becomes a theoretical fiction rather
131    than a practical freedom.  This is not sufficient.  In other words,
132    these binaries are not free software even if the source code they are
133    compiled from is free.
134    </p>
135    
136    <p>
137    One important way to modify a program is by merging in available free
138    subroutines and modules.  If the program's license says that you
139    cannot merge in a suitably licensed existing module &mdash; for instance, if it
140    requires you to be the copyright holder of any code you add &mdash; then the
141    license is too restrictive to qualify as free.
142    </p>
143    
144    <p>
145    Freedom 3 includes the freedom to release your modified versions
146    as free software.  A free license may also permit other ways of
147    releasing them; in other words, it does not have to be
148    a <a href="/copyleft/copyleft.html">copyleft</a> license.  However, a
149    license that requires modified versions to be nonfree does not qualify
150    as a free license.
151    </p>
152    
153    <p>
154    In order for these freedoms to be real, they must be permanent and
155    irrevocable as long as you do nothing wrong; if the developer of the
156    software has the power to revoke the license, or retroactively add
157    restrictions to its terms, without your doing anything wrong to give
158    cause, the software is not free.
159    </p>
160    
161  <p>  <p>
162  However, certain kinds of rules about the manner of distributing free  However, certain kinds of rules about the manner of distributing free
163  software are acceptable, when they don't conflict with the central  software are acceptable, when they don't conflict with the central
164  freedoms.  For example, copyleft (very simply stated) is the rule that  freedoms.  For example, copyleft (very simply stated) is the rule that
165  when redistributing the program, you cannot add restrictions to deny  when redistributing the program, you cannot add restrictions to deny
166  other people the central freedoms.  This rule does not conflict with  other people the central freedoms.  This rule does not conflict with
167  the central freedoms; rather it protects them.</p>  the central freedoms; rather it protects them.
168    </p>
169    
170  <p>  <p>
171  You may have paid money to get copies of free software, or you  In the GNU project, we use <a href="/copyleft/copyleft.html">
172  may have obtained copies at no charge.  But regardless of how you got  copyleft </a> to protect the four freedoms legally for everyone.  We
173  your copies, you always have the freedom to copy and change the  believe there are important reasons why
174  software, even to <a href="/philosophy/selling.html">sell copies</a>.</p>  <a href="/philosophy/pragmatic.html">it is better to use
175  <p>  copyleft</a>.  However,
176  ``Free software'' does not mean ``non-commercial''.  A free program  <a href="/philosophy/categories.html#Non-CopyleftedFreeSoftware">
177  must be available for commercial use, commercial development, and  noncopylefted free software</a> is ethical
178  commercial distribution.  Commercial development of free software is  too.  See <a href="/philosophy/categories.html">Categories of Free
179  no longer unusual; such free commercial software is very important.</p>  Software</a> for a description of how &ldquo;free software,&rdquo;
180  <p>  &ldquo;copylefted software&rdquo; and other categories of software
181  Rules about how to package a modified version are acceptable, if they  relate to each other.
182  don't substantively block your freedom to release modified versions.  </p>
183  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>  
184  <p>  <p>
185  Finally, note that criteria such as those stated in this free software  &ldquo;Free software&rdquo; does not mean &ldquo;noncommercial&rdquo;.  A free
186  definition require careful thought for their interpretation.  To  program must be available for commercial use, commercial development,
187  decide whether a specific software license qualifies as a free  and commercial distribution.  Commercial development of free software
188  software license, we judge it based on these criteria to determine  is no longer unusual; such free commercial software is very important.
189  whether it fits their spirit as well as the precise words.  If a  You may have paid money to get copies of free software, or you may have
190  license includes unconscionable restrictions, we reject it, even if we  obtained copies at no charge.  But regardless of how you got your copies,
191  did not anticipate the issue in these criteria.  Sometimes a license  you always have the freedom to copy and change the software, even to
192  requirement raises an issue that calls for extensive thought,  <a href="/philosophy/selling.html">sell copies</a>.
 including discussions with a lawyer, before we can decide if the  
 requirement is acceptable.  When we reach a conclusion about a new  
 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.  
193  </p>  </p>
194    
195  <p>  <p>
196  If that isn't possible, if you really need a new license, with our  Whether a change constitutes an improvement is a subjective matter.
197  help you can ensure that the license really is a Free Software license  If your right to modify a program is limited, in substance, to changes that
198  and avoid various practical problems.  someone else considers an improvement, that program is not free.
199  </p>  </p>
 <hr />  
200    
201  <p>  <p>
202  Another group has started using the term "open source" to mean  However, rules about how to package a modified version are acceptable,
203  something close (but not identical) to "free software".  We prefer the  if they don't substantively limit your freedom to release modified
204  term "free software" because, once you have heard it refers to freedom  versions, or your freedom to make and use modified versions privately.
205  rather than price, <a href="free-software-for-freedom.html">it calls  Thus, it is acceptable for the license to require that you change the
206  to mind freedom</a>.  The word "open" never does that.</p>  name of the modified version, remove a logo, or identify your
207    modifications as yours.  As long as these requirements are not so
208  <hr />  burdensome that they effectively hamper you from releasing your
209  <h4><a href="/philosophy/philosophy.html">Other Texts to Read</a></h4>  changes, they are acceptable; you're already making other changes to
210    the program, so you won't have trouble making a few more.
211    </p>
212  <!-- All pages on the GNU web server should have the section about    -->  
213  <!-- verbatim copying.  Please do NOT remove this without talking     -->  <p>
214  <!-- with the webmasters first. -->  Rules that &ldquo;if you make your version available in this way, you
215  <!-- Please make sure the copyright date is consistent with the document -->  must make it available in that way also&rdquo; can be acceptable too,
216  <!-- and that it is like this "2001, 2002" not this "2001-2002." -->  on the same condition.  An example of such an acceptable rule is one
217    saying that if you have distributed a
218  <div class="translations">  modified version and a previous developer asks for a copy of it, you
219  <p><a id="translations"></a>  must send one.  (Note that such a rule still leaves you the choice of
220  <b>Translations of this page</b>:<br />  whether to distribute your version at all.)  Rules that require release
221    of source code to the users for versions that you put into public use
222  <!-- Please keep this list alphabetical, and in the original -->  are also acceptable.
223  <!-- language if possible, otherwise default to English -->  </p>
224  <!-- If you do not have it English, please comment what the -->  
225  <!-- English is.  If you add a new language here, please -->  <p>
226  <!-- advise web-trans@gnu.org and add it to -->  A special issue arises when a license requires changing the name by
227  <!--    - in /home/www/bin/nightly-vars either TAGSLANG or WEBLANG -->  which the program will be invoked from other programs.  That
228  <!--    - in /home/www/html/server/standards/README.translations.html -->  effectively hampers you from releasing your changed version so that it
229  <!--      one of the lists under the section "Translations Underway" -->  can replace the original when invoked by those other programs.  This
230  <!--    - if there is a translation team, you also have to add an alias -->  sort of requirement is acceptable only if there's a suitable aliasing
231  <!--      to mail.gnu.org:/com/mailer/aliases -->  facility that allows you to specify the original program's name as an
232  <!-- Please also check you have the 2 letter language code right versus -->  alias for the modified version.</p>
233  <!--     http://www.w3.org/WAI/ER/IG/ert/iso639.htm -->  
234  [  <p>
235    <a href="/philosophy/free-sw.ca.html">Catal&#x00e0;</a>       <!-- Catalan -->  Sometimes government <a id="exportcontrol">export control regulations</a>
236    and trade sanctions can constrain your freedom to distribute copies of
237  <!-- Chinese (Simplified) -->  programs internationally.  Software developers do not have the power to
238  | <a href="/philosophy/free-sw.cn.html">&#x7b80;&#x4f53;&#x4e2d;&#x6587;</a>  eliminate or override these restrictions, but what they can and must do
239    is refuse to impose them as conditions of use of the program.  In this
240  <!-- Chinese (Traditional) -->  way, the restrictions will not affect activities and people outside the
241  | <a href="/philosophy/free-sw.zh.html">&#x7e41;&#x9ad4;&#x4e2d;&#x6587;</a>  jurisdictions of these governments.  Thus, free software licenses
242    must not require obedience to any nontrivial export regulations as a
243  | <a href="/philosophy/free-sw.cs.html">&#x010c;esky</a>        <!-- Czech -->  condition of exercising any of the essential freedoms.
244  | <a href="/philosophy/free-sw.da.html">Dansk</a>       <!-- Danish -->  </p>
245  | <a href="/philosophy/free-sw.de.html">Deutsch</a>     <!-- German -->  
246  | <a href="/philosophy/free-sw.html">English</a>  <p>
247  | <a href="/philosophy/free-sw.es.html">Espa&#x00f1;ol</a>      <!-- Spanish -->  Merely mentioning the existence of export regulations, without making
248  | <a href="/philosophy/free-sw.fr.html">Fran&#x00e7;ais</a>     <!-- French -->  them a condition of the license itself, is acceptable since it does
249  | <a href="/philosophy/free-sw.gl.html">Galego</a>      <!-- Galician -->  not restrict users.  If an export regulation is actually trivial for
250  | <a href="/philosophy/free-sw.he.html">&#x05e2;&#x05d1;&#x05e8;&#x05d9;&#x05ea;</a>    <!-- Hebrew -->  free software, then requiring it as a condition is not an actual
251  | <a href="/philosophy/free-sw.hr.html">Hrvatski</a>    <!-- Croatian -->  problem; however, it is a potential problem, since a later change in
252  | <a href="/philosophy/free-sw.id.html">Bahasa Indonesia</a>    <!-- Indonesian -->  export law could make the requirement nontrivial and thus render the
253  | <a href="/philosophy/free-sw.it.html">Italiano</a>    <!-- Italian -->  software nonfree.
 | <a href="/philosophy/free-sw.ja.html">&#x65e5;&#x672c;&#x8a9e;</a>    <!-- Japanese -->  
 | <a href="/philosophy/free-sw.ko.html">&#xd55c;&#xad6d;&#xc5b4;</a>    <!-- Korean -->  
 | <a href="/philosophy/free-sw.hu.html">Magyar</a>      <!-- Hungarian -->  
 | <a href="/philosophy/free-sw.nl.html">Nederlands</a>  <!-- Dutch -->  
 | <a href="/philosophy/free-sw.no.html">Norsk</a>       <!-- Norwegian -->  
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 ]  
254  </p>  </p>
 </div>  
255    
 <div class="copyright">  
256  <p>  <p>
257  Return to the <a href="/home.html">GNU Project home page</a>.  A free license may not require compliance with the license of a
258    nonfree program.  Thus, for instance, if a license requires you to
259    comply with the licenses of &ldquo;all the programs you use&rdquo;, in
260    the case of a user that runs nonfree programs this would require
261    compliance with the licenses of those nonfree programs; that makes the
262    license nonfree.
263  </p>  </p>
264    
265  <p>  <p>
266  Please send FSF &amp; GNU inquiries to  It is acceptable for a free license to specify which jurisdiction's
267  <a href="mailto:gnu@gnu.org"><em>gnu@gnu.org</em></a>.  law applies, or where litigation must be done, or both.
 There are also <a href="/home.html#ContactInfo">other ways to contact</a>  
 the FSF.  
 <br />  
 Please send broken links and other corrections (or suggestions) to  
 <a href="mailto:webmasters@gnu.org"><em>webmasters@gnu.org</em></a>.  
268  </p>  </p>
269    
270  <p>  <p>
271  Please see the  Most free software licenses are based on copyright, and there are limits
272  <a href="/server/standards/README.translations.html">Translations  on what kinds of requirements can be imposed through copyright.  If a
273  README</a> for information on coordinating and submitting  copyright-based license respects freedom in the ways described above, it
274  translations of this article.  is unlikely to have some other sort of problem that we never anticipated
275    (though this does happen occasionally).  However, some free software
276    licenses are based on contracts, and contracts can impose a much larger
277    range of possible restrictions.  That means there are many possible ways
278    such a license could be unacceptably restrictive and nonfree.
279  </p>  </p>
280    
281  <p>  <p>
282  Copyright (C) 1996, 1997, 1998, 1999, 2000, 2001, 2002, 2003, 2004 Free  We can't possibly list all the ways that might happen.  If a
283  Software Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  contract-based license restricts the user in an unusual way that
284  02111,  USA  copyright-based licenses cannot, and which isn't mentioned here as
285  <br />  legitimate, we will have to think about it, and we will probably conclude
286  Verbatim copying and distribution of this entire article is  it is nonfree.
 permitted in any medium without royalty provided this notice is  
 preserved.  
287  </p>  </p>
288    
289  <p>  <p>
290  Updated:  When talking about free software, it is best to avoid using terms
291    like &ldquo;give away&rdquo; or &ldquo;for free,&rdquo; because those terms imply that
292    the issue is about price, not freedom.  Some common terms such
293    as &ldquo;piracy&rdquo; embody opinions we hope you won't endorse.  See
294    <a href="/philosophy/words-to-avoid.html">Confusing Words and Phrases that
295    are Worth Avoiding</a> for a discussion of these terms.  We also have
296    a list of proper <a href="/philosophy/fs-translations.html">translations of
297    &ldquo;free software&rdquo;</a> into various languages.
298    </p>
299    
300    <p>
301    Finally, note that criteria such as those stated in this free software
302    definition require careful thought for their interpretation.  To decide
303    whether a specific software license qualifies as a free software license,
304    we judge it based on these criteria to determine whether it fits their
305    spirit as well as the precise words.  If a license includes unconscionable
306    restrictions, we reject it, even if we did not anticipate the issue
307    in these criteria.  Sometimes a license requirement raises an issue
308    that calls for extensive thought, including discussions with a lawyer,
309    before we can decide if the requirement is acceptable.  When we reach
310    a conclusion about a new issue, we often update these criteria to make
311    it easier to see why certain licenses do or don't qualify.
312    </p>
313    
314    <p>
315    If you are interested in whether a specific license qualifies as a free
316    software license, see our <a href="/licenses/license-list.html">list
317    of licenses</a>.  If the license you are concerned with is not
318    listed there, you can ask us about it by sending us email at
319    <a href="mailto:licensing@gnu.org">&lt;licensing@gnu.org&gt;</a>.
320    </p>
321    
322    <p>
323    If you are contemplating writing a new license, please contact the
324    Free Software Foundation first by writing to that address. The
325    proliferation of different free software licenses means increased work
326    for users in understanding the licenses; we may be able to help you
327    find an existing free software license that meets your needs.
328    </p>
329    
330    <p>
331    If that isn't possible, if you really need a new license, with our
332    help you can ensure that the license really is a free software license
333    and avoid various practical problems.
334    </p>
335    
336    <h3 id="beyond-software">Beyond Software</h3>
337    
338    <p>
339    <a href="/philosophy/free-doc.html">Software manuals must be free</a>,
340    for the same reasons that software must be free, and because the
341    manuals are in effect part of the software.
342    </p>
343    
344    <p>
345    The same arguments also make sense for other kinds of works of
346    practical use &mdash; that is to say, works that embody useful knowledge,
347    such as educational works and reference
348    works.  <a href="http://wikipedia.org">Wikipedia</a> is the best-known
349    example.
350    </p>
351    
352    <p>
353    Any kind of work <em>can</em> be free, and the definition of free software
354    has been extended to a definition of <a href="http://freedomdefined.org/">
355    free cultural works</a> applicable to any kind of works.
356    </p>
357    
358    <h3 id="open-source">Open Source?</h3>
359    
360    <p>
361    Another group has started using the term &ldquo;open source&rdquo; to mean
362    something close (but not identical) to &ldquo;free software&rdquo;.  We
363    prefer the term &ldquo;free software&rdquo; because, once you have heard that
364    it refers to freedom rather than price, it calls to mind freedom.  The
365    word &ldquo;open&rdquo; <a href="/philosophy/open-source-misses-the-point.html">
366    never refers to freedom</a>.
367    </p>
368    
369    <h3 id="History">History</h3>
370    
371    <p>From time to time we revise this Free Software Definition.  Here is
372    the list of substantive changes, along with links to show exactly what
373    was changed.</p>
374    
375    <ul>
376    
377    <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
378    1.131</a>: A free license may not require compliance with a nonfree license
379    of another program.</li>
380    
381    <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
382    1.129</a>: State explicitly that choice of law and choice of forum
383    specifications are allowed.  (This was always our policy.)</li>
384    
385    <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
386    1.122</a>: An export control requirement is a real problem if the
387    requirement is nontrivial; otherwise it is only a potential problem.</li>
388    
389    <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
390    1.118</a>: Clarification: the issue is limits on your right to modify,
391    not on what modifications you have made.  And modifications are not limited
392    to &ldquo;improvements&rdquo;</li>
393    
394    <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
395    1.111</a>: Clarify 1.77 by saying that only
396    retroactive <em>restrictions</em> are unacceptable.  The copyright
397    holders can always grant additional <em>permission</em> for use of the
398    work by releasing the work in another way in parallel.</li>
399    
400    <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
401    1.105</a>: Reflect, in the brief statement of freedom 1, the point
402    (already stated in version 1.80) that it includes really using your modified
403    version for your computing.</li>
404    
405    <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
406    1.92</a>: Clarify that obfuscated code does not qualify as source code.</li>
407    
408    <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
409    1.90</a>: Clarify that freedom 3 means the right to distribute copies
410    of your own modified or improved version, not a right to participate
411    in someone else's development project.</li>
412    
413    <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
414    1.89</a>: Freedom 3 includes the right to release modified versions as
415    free software.</li>
416    
417    <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
418    1.80</a>: Freedom 1 must be practical, not just theoretical;
419    i.e., no tivoization.</li>
420    
421    <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
422    1.77</a>: Clarify that all retroactive changes to the license are
423    unacceptable, even if it's not described as a complete
424    replacement.</li>
425    
426    <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
427    1.74</a>: Four clarifications of points not explicit enough, or stated
428    in some places but not reflected everywhere:
429    <ul>
430    <li>"Improvements" does not mean the license can
431    substantively limit what kinds of modified versions you can release.
432    Freedom 3 includes distributing modified versions, not just changes.</li>
433    <li>The right to merge in existing modules
434    refers to those that are suitably licensed.</li>
435    <li>Explicitly state the conclusion of the point about export controls.</li>
436    <li>Imposing a license change constitutes revoking the old license.</li>
437    </ul>
438    </li>
439    
440    <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
441    1.57</a>: Add &quot;Beyond Software&quot; section.</li>
442    
443    <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
444    1.46</a>: Clarify whose purpose is significant in the freedom to run
445    the program for any purpose.</li>
446    
447    <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
448    1.41</a>: Clarify wording about contract-based licenses.</li>
449    
450    <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
451    1.40</a>: Explain that a free license must allow to you use other
452    available free software to create your modifications.</li>
453    
454    <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
455    1.39</a>: Note that it is acceptable for a license to require you to
456    provide source for versions of the software you put into public
457    use.</li>
458    
459    <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
460    1.31</a>: Note that it is acceptable for a license to require you to
461    identify yourself as the author of modifications.  Other minor
462    clarifications throughout the text.</li>
463    
464    <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
465    1.23</a>: Address potential problems related to contract-based
466    licenses.</li>
467    
468    <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
469    1.16</a>: Explain why distribution of binaries is important.</li>
470    
471    <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
472    1.11</a>: Note that a free license may require you to send a copy of
473    versions you distribute to the author.</li>
474    
475    </ul>
476    
477    <p>There are gaps in the version numbers shown above because there are
478    other changes in this page that do not affect the definition or its
479    interpretations.  For instance, the list does not include changes in
480    asides, formatting, spelling, punctuation, or other parts of the page.
481    You can review the complete list of changes to the page through
482    the <a href="http://web.cvs.savannah.gnu.org/viewvc/www/philosophy/free-sw.html?root=www&amp;view=log">cvsweb
483    interface</a>.</p>
484    
485    
486    </div><!-- for id="content", starts in the include above -->
487    <!--#include virtual="/server/footer.html" -->
488    <div id="footer">
489    <div class="unprintable">
490    
491    <p>Please send general FSF &amp; GNU inquiries to
492    <a href="mailto:gnu@gnu.org">&lt;gnu@gnu.org&gt;</a>.
493    There are also <a href="/contact/">other ways to contact</a>
494    the FSF.  Broken links and other corrections or suggestions can be sent
495    to <a href="mailto:webmasters@gnu.org">&lt;webmasters@gnu.org&gt;</a>.</p>
496    
497    <p><!-- TRANSLATORS: Ignore the original text in this paragraph,
498            replace it with the translation of these two:
499    
500            We work hard and do our best to provide accurate, good quality
501            translations.  However, we are not exempt from imperfection.
502            Please send your comments and general suggestions in this regard
503            to <a href="mailto:web-translators@gnu.org">
504            &lt;web-translators@gnu.org&gt;</a>.</p>
505    
506            <p>For information on coordinating and submitting translations of
507            our web pages, see <a
508            href="/server/standards/README.translations.html">Translations
509            README</a>. -->
510    Please see the <a
511    href="/server/standards/README.translations.html">Translations
512    README</a> for information on coordinating and submitting translations
513    of this article.</p>
514    </div>
515    
516    <!-- Regarding copyright, in general, standalone pages (as opposed to
517         files generated as part of manuals) on the GNU web server should
518         be under CC BY-ND 3.0 US.  Please do NOT change or remove this
519         without talking with the webmasters or licensing team first.
520         Please make sure the copyright date is consistent with the
521         document.  For web pages, it is ok to list just the latest year the
522         document was modified, or published.
523        
524         If you wish to list earlier years, that is ok too.
525         Either "2001, 2002, 2003" or "2001-2003" are ok for specifying
526         years, as long as each year in the range is in fact a copyrightable
527         year, i.e., a year in which the document was published (including
528         being publicly visible on the web or in a revision control system).
529        
530         There is more detail about copyright years in the GNU Maintainers
531         Information document, www.gnu.org/prep/maintain. -->
532    
533    <p>Copyright &copy; 1996-2002, 2004-2007, 2009, 2010, 2012, 2013
534    Free Software Foundation, Inc.</p>
535    
536    <p>This page is licensed under a <a rel="license"
537    href="http://creativecommons.org/licenses/by-nd/3.0/us/">Creative
538    Commons Attribution-NoDerivs 3.0 United States License</a>.</p>
539    
540    <!--#include virtual="/server/bottom-notes.html" -->
541    
542    <p class="unprintable">Updated:
543  <!-- timestamp start -->  <!-- timestamp start -->
544  $Date$ $Author$  $Date$
545  <!-- timestamp end -->  <!-- timestamp end -->
546  </p>  </p>
547  </div>  </div>
548    </div>
549  </body>  </body>
550  </html>  </html>

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