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4    - GNU Project - Free Software Foundation</title>
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16    
17  <h2>The Free Software Definition</h2>  <h2>What is free software?</h2>
18    
19  <p>  <div class="article">
20  We maintain this free software definition to show clearly what must be  <h3>The Free Software Definition</h3>
21  true about a particular software program for it to be considered free  
22  software.  From time to time we revise this definition to clarify it.  <blockquote class="note" id="fsf-licensing"><p style="font-size: 80%">
23  If you would like to review the changes we've made, please see  Have a question about free software licensing not answered here?
24  the <a href="#History">History section</a> below for more information.  See our other <a href="http://www.fsf.org/licensing">licensing resources</a>,
25    and if necessary contact the FSF Compliance Lab
26    at <a href="mailto:licensing@fsf.org">licensing@fsf.org</a>.</p>
27    </blockquote>
28    
29    <div class="comment">
30    <p>
31    The free software definition presents the criteria for whether a
32    particular software program qualifies as free software.  From time to
33    time we revise this definition, to clarify it or to resolve questions
34    about subtle issues.  See the <a href="#History">History section</a>
35    below for a list of changes that affect the definition of free
36    software.
37  </p>  </p>
38    
39  <p>  <p>
40  <q>Free software</q> is a matter of liberty, not price.  To understand  &ldquo;Open source&rdquo; is something different: it has a very
41  the concept, you should think of <q>free</q> as in <q>free speech,</q>  different philosophy based on different values.  Its practical
42  not as in <q>free beer.</q>  definition is different too, but nearly all open source programs are
43    in fact free.  We explain the
44    difference in <a href="/philosophy/open-source-misses-the-point.html">
45    Why &ldquo;Open Source&rdquo; misses the point of Free Software</a>.
46  </p>  </p>
47    </div>
48    
49  <p>  <p>
50  Free software is a matter of the users' freedom to run, copy, distribute,  &ldquo;Free software&rdquo; means software that respects users'
51  study, change and improve the software.  More precisely, it refers to  freedom and community.  Roughly, it means that <b>the users have the
52  four kinds of freedom, for the users of the software:  freedom to run, copy, distribute, study, change and improve the
53    software</b>.  Thus, &ldquo;free software&rdquo; is a matter of
54    liberty, not price.  To understand the concept, you should think of
55    &ldquo;free&rdquo; as in &ldquo;free speech,&rdquo; not as in
56    &ldquo;free beer&rdquo;.  We sometimes call it &ldquo;libre
57    software,&rdquo; borrowing the French or Spanish word for
58    &ldquo;free&rdquo; as in freedom, to show we do not mean the software
59    is gratis.
60  </p>  </p>
61    
62  <ul>  <p>
63    <li>The freedom to run the program, for any purpose (freedom 0).</li>  We campaign for these freedoms because everyone deserves them.  With
64    <li>The freedom to study how the program works, and adapt it to  these freedoms, the users (both individually and collectively) control
65        your needs (freedom 1). Access to the source code is a precondition  the program and what it does for them.  When users don't control the
66        for this.  program, we call it a &ldquo;nonfree&rdquo; or
67    &ldquo;proprietary&rdquo; program.  The nonfree program controls the
68    users, and the developer controls the program; this makes the
69    program <a href="/philosophy/free-software-even-more-important.html">
70    an instrument of unjust power</a>.
71    </p>
72    
73    <h4> The four essential freedoms</h4>
74    
75    <p>
76    A program is free software if the program's users have the
77    four essential freedoms: <a href="#f1">[1]</a>
78    </p>
79    
80    <ul class="important">
81      <li>The freedom to run the program as you wish,
82          for any purpose (freedom 0).</li>
83      <li>The freedom to study how the program works, and change it so it
84          does your computing as you wish (freedom 1). Access to the source
85          code is a precondition for this.
86    </li>    </li>
87    <li>The freedom to redistribute copies so you can help your neighbor    <li>The freedom to redistribute copies so you can help others
88        (freedom 2).        (freedom 2).
89    </li>    </li>
90    <li>The freedom to improve the program, and release your improvements    <li>The freedom to distribute copies of your modified versions
91        (and modified versions in general)        to others (freedom 3).  By doing this you can give the whole
92        to the public, so that the whole community benefits (freedom 3).        community a chance to benefit from your changes.
93        Access to the source code is a precondition for this.        Access to the source code is a precondition for this.
94    </li>    </li>
95  </ul>  </ul>
96    
97  <p>  <p>
98  A program is free software if users have all of these freedoms.  Thus,  A program is free software if it gives users adequately all of these
99  you should be free to redistribute copies, either with or without  freedoms.  Otherwise, it is nonfree.  While we can distinguish various
100  modifications, either gratis or charging a fee for distribution, to  nonfree distribution schemes in terms of how far they fall short of
101  <a href="#exportcontrol">anyone anywhere</a>.  Being free to do these  being free, we consider them all equally unethical.</p>
102  things means (among other things) that you do not have to ask or pay  
103  for permission.  <p>In any given scenario, these freedoms must apply to whatever code
104    we plan to make use of, or lead others to make use of.  For instance,
105    consider a program A which automatically launches a program B to
106    handle some cases.  If we plan to distribute A as it stands, that
107    implies users will need B, so we need to judge whether both A and B
108    are free.  However, if we plan to modify A so that it doesn't use B,
109    only A needs to be free; B is not pertinent to that plan.</p>
110    
111    <p>
112    &ldquo;Free software&rdquo; does not mean &ldquo;noncommercial&rdquo;.
113    On the contrary, a free program must be available for commercial use,
114    commercial development, and commercial distribution.  This policy is
115    of fundamental importance&mdash;without this, free software could not
116    achieve its aims.
117  </p>  </p>
118    
119  <p>  <p>
120  You should also have the freedom to make modifications and use them  We want to invite everyone to use the GNU system, including businesses
121  privately in your own work or play, without even mentioning that they  and their workers.  That requires allowing commercial use.  We hope
122  exist.  If you do publish your changes, you should not be required to  that free replacement programs will supplant comparable proprietary
123  notify anyone in particular, or in any particular way.  programs, but they can't do that if businesses are forbidden to use
124    them.  We want commercial products that contain software to include
125    the GNU system, and that would constitute commercial distribution for
126    a price.  Commercial development of free software is no longer
127    unusual; such free commercial software is very important.  Paid,
128    professional support for free software fills an important need.
129  </p>  </p>
130    
131  <p>  <p>
132    Thus, to exclude commercial use, commercial development or commercial
133    distribution would hobble the free software community and obstruct its
134    path to success.  We must conclude that a program licensed with such
135    restrictions does not qualify as free software.
136    </p>
137    
138    <p>
139    A free program must offer the four freedoms to any would-be user that
140    obtains a copy of the software, who has complied thus far with the
141    conditions of the free license covering the software in any previous
142    distribution of it.  Putting some of the freedoms off limits to some
143    users, or requiring that users pay, in money or in kind, to exercise
144    them, is tantamount to not granting the freedoms in question, and thus
145    renders the program nonfree.
146    </p>
147    
148    <p>
149    You may have paid money to get copies of a free program, or you may
150    have obtained copies at no charge.  But regardless of how you got your
151    copies, you always have the freedom to copy and change the software,
152    even to <a href="/philosophy/selling.html">sell copies</a>.
153    </p>
154    
155    <h3>Clarifying the boundary between free and nonfree</h3>
156    
157    <p>In the rest of this article we explain more precisely how far the
158    various freedoms need to extend, on various issues, in order for a
159    program to be free.</p>
160    
161    <h4>The freedom to run the program as you wish</h4>
162    
163    <p>
164  The freedom to run the program means the freedom for any kind of person  The freedom to run the program means the freedom for any kind of person
165  or organization to use it on any kind of computer system, for any kind of  or organization to use it on any kind of computer system, for any kind of
166  overall job and purpose, without being required to communicate about it  overall job and purpose, without being required to communicate about it
167  with the developer or any other specific entity.  In this freedom, it is  with the developer or any other specific entity.  In this freedom, it is
168  the <em>user's</em> purpose that matters, not the <em>developer's</em>  the <em>user's</em> purpose that matters, not the <em>developer's</em>
169  purpose; you as a user are free to run a program for your purposes,  purpose; you as a user are free to run the program for your purposes,
170  and if you distribute it to someone else, she is then free to run it  and if you distribute it to someone else, she is then free to run it
171  for her purposes, but you are not entitled to impose your purposes on her.  for her purposes, but you are not entitled to impose your purposes on her.
172  </p>  </p>
173    
174  <p>  <p>
175  The freedom to redistribute copies must include binary or executable  The freedom to run the program as you wish means that you are not
176  forms of the program, as well as source code, for both modified and  forbidden or stopped from making it run.  This has nothing to do with what
177  unmodified versions.  (Distributing programs in runnable form is necessary  functionality the program has, whether it is technically capable of
178  for conveniently installable free operating systems.)  It is ok if there  functioning in any given environment, or whether it is useful for any
179  is no way to produce a binary or executable form for a certain program  particular computing activity.</p>
180  (since some languages don't support that feature), but you must have the  
181  freedom to redistribute such forms should you find or develop a way to  <p>For example, if the code arbitrarily rejects certain meaningful
182  make them.  inputs&mdash;or even fails unconditionally&mdash;that may make the
183    program less useful, perhaps even totally useless, but it does not
184    deny users the freedom to run the program, so it does not conflict
185    with freedom 0.  If the program is free, the users can overcome the
186    loss of usefulness, because freedoms 1 and 3 permit users and
187    communities to make and distribute modified versions without the
188    arbitrary nuisance code.</p>
189    
190    <p>&ldquo;As you wish&rdquo; includes, optonally, &ldquo;not at
191    all&rdquo; if that is what you wish.  So there is no need for a
192    separate &ldquo;freedom not to run a program.&rdquo;<p>
193    
194    <h4>The freedom to study the source code and make changes</h4>
195    
196    <p>
197    In order for freedoms 1 and 3 (the freedom to make changes and the
198    freedom to publish the changed versions) to be meaningful, you need to have
199    access to the source code of the program.  Therefore, accessibility of
200    source code is a necessary condition for free software.  Obfuscated
201    &ldquo;source code&rdquo; is not real source code and does not count
202    as source code.
203  </p>  </p>
204    
205  <p>  <p>
206  In order for the freedoms to make changes, and to publish improved  Freedom 1 includes the freedom to use your changed version in place of
207  versions, to be meaningful, you must have access to the source code of  the original.  If the program is delivered in a product designed to
208  the program.  Therefore, accessibility of source code is a necessary  run someone else's modified versions but refuse to run yours &mdash; a
209  condition for free software.  practice known as &ldquo;tivoization&rdquo; or &ldquo;lockdown&rdquo;,
210    or (in its practitioners' perverse terminology) as &ldquo;secure
211    boot&rdquo; &mdash; freedom 1 becomes an empty pretense rather than a
212    practical reality.  These binaries are not free
213    software even if the source code they are compiled from is free.
214  </p>  </p>
215    
216  <p>  <p>
217  One important way to modify a program is by merging in available free  One important way to modify a program is by merging in available free
218  subroutines and modules.  If the program's license says that you  subroutines and modules.  If the program's license says that you
219  cannot merge in a suitably-licensed existing module, such as if it  cannot merge in a suitably licensed existing module &mdash; for instance, if it
220  requires you to be the copyright holder of any code you add, then the  requires you to be the copyright holder of any code you add &mdash; then the
221  license is too restrictive to qualify as free.  license is too restrictive to qualify as free.
222  </p>  </p>
223    
224  <p>  <p>
225  In order for these freedoms to be real, they must be irrevocable as  Whether a change constitutes an improvement is a subjective matter.
226  long as you do nothing wrong; if the developer of the software has the  If your right to modify a program is limited, in substance, to changes that
227  power to revoke the license, or replace it with a different license  someone else considers an improvement, that program is not free.
 (since this implies revoking the old license),  
 without your doing anything wrong to give cause, the software is not  
 free.  
228  </p>  </p>
229    
230  <p>  <p>
231  However, certain kinds of rules about the manner of distributing free  One special case of freedom 1 is to delete the program's code so it
232  software are acceptable, when they don't conflict with the central  returns after doing nothing, or make it invoke some other program.
233  freedoms.  For example, copyleft (very simply stated) is the rule that  Thus, freedom 1 includes the &ldquo;freedom to delete the program.&rdquo;
234  when redistributing the program, you cannot add restrictions to deny  </p>
235  other people the central freedoms.  This rule does not conflict with  
236  the central freedoms; rather it protects them.  <h4>The freedom to redistribute if you wish: basic requirements</h4>
237    
238    <p>Freedom to distribute (freedoms 2 and 3) means you are free to
239    redistribute copies, either with or without modifications, either
240    gratis or charging a fee for distribution, to
241    <a href="#exportcontrol">anyone anywhere</a>.  Being free to do these
242    things means (among other things) that you do not have to ask or pay
243    for permission to do so.
244  </p>  </p>
245    
246  <p>  <p>
247  <q>Free software</q> does not mean <q>non-commercial.</q>  A free  You should also have the freedom to make modifications and use them
248  program must be available for commercial use, commercial development,  privately in your own work or play, without even mentioning that they
249  and commercial distribution.  Commercial development of free software  exist.  If you do publish your changes, you should not be required to
250  is no longer unusual; such free commercial software is very important.  notify anyone in particular, or in any particular way.
 You may have paid money to get copies of free software, or you 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>.  
251  </p>  </p>
252    
253  <p>  <p>
254  Whether a change constitutes an improvement is a subjective matter.  Freedom 3 includes the freedom to release your modified versions
255  If your modifications are limited, in substance, to changes that  as free software.  A free license may also permit other ways of
256  someone else considers an improvement, that is not freedom.  releasing them; in other words, it does not have to be
257    a <a href="/copyleft/copyleft.html">copyleft</a> license.  However, a
258    license that requires modified versions to be nonfree does not qualify
259    as a free license.
260  </p>  </p>
261    
262  <p>  <p>
263  However, rules about how to package a modified version are acceptable, if they  The freedom to redistribute copies must include binary or executable
264  don't substantively limit your freedom to release modified versions, or  forms of the program, as well as source code, for both modified and
265  your freedom to make and use modified versions privately.  Rules that <q>if  unmodified versions.  (Distributing programs in runnable form is necessary
266  you make your version available in this way, you must make it available in  for conveniently installable free operating systems.)  It is OK if there
267  that way also</q> can be acceptable too, on the same condition.  (Note that  is no way to produce a binary or executable form for a certain program
268  such a rule still leaves you the choice of whether to publish your version  (since some languages don't support that feature), but you must have the
269  at all.)  Rules that require release of source code to the users for  freedom to redistribute such forms should you find or develop a way to
270  versions that you put into public use are also acceptable.  It is also  make them.
 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.  
271  </p>  </p>
272    
273    <h4>Copyleft</h4>
274    
275  <p>  <p>
276  In the GNU project, we use  Certain kinds of rules about the manner of distributing free
277  <q><a href="/copyleft/copyleft.html">copyleft</a></q>  software are acceptable, when they don't conflict with the central
278  to protect these freedoms legally for everyone.  But  freedoms.  For example, <a href="/copyleft/copyleft.html">copyleft</a>
279  <a href="/philosophy/categories.html#Non-CopyleftedFreeSoftware">non-copylefted  (very simply stated) is the rule that when redistributing the program,
280  free software</a> also exists.  We believe there are important reasons why  you cannot add restrictions to deny other people the central freedoms.
281  <a href="/philosophy/pragmatic.html"> it is better to use copyleft</a>,  This rule does not conflict with the central freedoms; rather it
282  but if your program is non-copylefted free software, it is still basically  protects them.
 ethical.  
283  </p>  </p>
284    
285  <p>  <p>
286  See <a href="/philosophy/categories.html">Categories of Free Software</a>  In the GNU project, we use copyleft to protect the four freedoms
287  for a description of how <q>free software,</q> <q>copylefted software</q>  legally for everyone.  We believe there are important reasons why
288  and other categories of software relate to each other.  <a href="/philosophy/pragmatic.html">it is better to use
289    copyleft</a>.  However,
290    <a href="/philosophy/categories.html#Non-CopyleftedFreeSoftware">
291    noncopylefted free software</a> is ethical
292    too.  See <a href="/philosophy/categories.html">Categories of Free
293    Software</a> for a description of how &ldquo;free software,&rdquo;
294    &ldquo;copylefted software&rdquo; and other categories of software
295    relate to each other.
296  </p>  </p>
297    
298    <h4>Rules about packaging and distribution details</h4>
299    
300    <p>
301    Rules about how to package a modified version are acceptable,
302    if they don't substantively limit your freedom to release modified
303    versions, or your freedom to make and use modified versions privately.
304    Thus, it is acceptable for the license to require that you change the
305    name of the modified version, remove a logo, or identify your
306    modifications as yours.  As long as these requirements are not so
307    burdensome that they effectively hamper you from releasing your
308    changes, they are acceptable; you're already making other changes to
309    the program, so you won't have trouble making a few more.
310    </p>
311    
312    <p>
313    Rules that &ldquo;if you make your version available in this way, you
314    must make it available in that way also&rdquo; can be acceptable too,
315    on the same condition.  An example of such an acceptable rule is one
316    saying that if you have distributed a
317    modified version and a previous developer asks for a copy of it, you
318    must send one.  (Note that such a rule still leaves you the choice of
319    whether to distribute your version at all.)  Rules that require release
320    of source code to the users for versions that you put into public use
321    are also acceptable.
322    </p>
323    
324    <p>
325    A special issue arises when a license requires changing the name by
326    which the program will be invoked from other programs.  That
327    effectively hampers you from releasing your changed version so that it
328    can replace the original when invoked by those other programs.  This
329    sort of requirement is acceptable only if there's a suitable aliasing
330    facility that allows you to specify the original program's name as an
331    alias for the modified version.</p>
332    
333    <h4>Export regulations</h4>
334    
335  <p>  <p>
336  Sometimes government <a id="exportcontrol">export control regulations</a>  Sometimes government <a id="exportcontrol">export control regulations</a>
337  and trade sanctions can constrain your freedom to distribute copies of  and trade sanctions can constrain your freedom to distribute copies of
# Line 174  eliminate or override these restrictions Line 340  eliminate or override these restrictions
340  is refuse to impose them as conditions of use of the program.  In this  is refuse to impose them as conditions of use of the program.  In this
341  way, the restrictions will not affect activities and people outside the  way, the restrictions will not affect activities and people outside the
342  jurisdictions of these governments.  Thus, free software licenses  jurisdictions of these governments.  Thus, free software licenses
343  must not require obedience to any export regulations a condition of  must not require obedience to any nontrivial export regulations as a
344  any of the essential freedoms.  condition of exercising any of the essential freedoms.
345    </p>
346    
347    <p>
348    Merely mentioning the existence of export regulations, without making
349    them a condition of the license itself, is acceptable since it does
350    not restrict users.  If an export regulation is actually trivial for
351    free software, then requiring it as a condition is not an actual
352    problem; however, it is a potential problem, since a later change in
353    export law could make the requirement nontrivial and thus render the
354    software nonfree.
355    </p>
356    
357    <h4>Legal considerations</h4>
358    
359    <p>
360    In order for these freedoms to be real, they must be permanent and
361    irrevocable as long as you do nothing wrong; if the developer of the
362    software has the power to revoke the license, or retroactively add
363    restrictions to its terms, without your doing anything wrong to give
364    cause, the software is not free.
365    </p>
366    
367    <p>
368    A free license may not require compliance with the license of a
369    nonfree program.  Thus, for instance, if a license requires you to
370    comply with the licenses of &ldquo;all the programs you use&rdquo;, in
371    the case of a user that runs nonfree programs this would require
372    compliance with the licenses of those nonfree programs; that makes the
373    license nonfree.
374    </p>
375    
376    <p>
377    It is acceptable for a free license to specify which jurisdiction's
378    law applies, or where litigation must be done, or both.
379  </p>  </p>
380    
381    <h4>Contract-based licenses</h4>
382    
383  <p>  <p>
384  Most free software licenses are based on copyright, and there are limits  Most free software licenses are based on copyright, and there are limits
385  on what kinds of requirements can be imposed through copyright.  If a  on what kinds of requirements can be imposed through copyright.  If a
# Line 186  is unlikely to have some other sort of p Line 388  is unlikely to have some other sort of p
388  (though this does happen occasionally).  However, some free software  (though this does happen occasionally).  However, some free software
389  licenses are based on contracts, and contracts can impose a much larger  licenses are based on contracts, and contracts can impose a much larger
390  range of possible restrictions.  That means there are many possible ways  range of possible restrictions.  That means there are many possible ways
391  such a license could be unacceptably restrictive and non-free.  such a license could be unacceptably restrictive and nonfree.
392  </p>  </p>
393    
394  <p>  <p>
# Line 194  We can't possibly list all the ways that Line 396  We can't possibly list all the ways that
396  contract-based license restricts the user in an unusual way that  contract-based license restricts the user in an unusual way that
397  copyright-based licenses cannot, and which isn't mentioned here as  copyright-based licenses cannot, and which isn't mentioned here as
398  legitimate, we will have to think about it, and we will probably conclude  legitimate, we will have to think about it, and we will probably conclude
399  it is non-free.  it is nonfree.
400  </p>  </p>
401    
402    <h4>Use the right words when talking about free software</h4>
403    
404  <p>  <p>
405  When talking about free software, it is best to avoid using terms  When talking about free software, it is best to avoid using terms
406  like <q>give away</q> or <q>for free,</q> because those terms imply that  like &ldquo;give away&rdquo; or &ldquo;for free,&rdquo; because those terms imply that
407  the issue is about price, not freedom.  Some common terms such  the issue is about price, not freedom.  Some common terms such
408  as <q>piracy</q> embody opinions we hope you won't endorse.  See  as &ldquo;piracy&rdquo; embody opinions we hope you won't endorse.  See
409  <a href="/philosophy/words-to-avoid.html">Confusing Words and Phrases that  <a href="/philosophy/words-to-avoid.html">Confusing Words and Phrases that
410  are Worth Avoiding</a> for a discussion of these terms.  We also have  are Worth Avoiding</a> for a discussion of these terms.  We also have
411  a list of <a href="/philosophy/fs-translations.html">translations of  a list of proper <a href="/philosophy/fs-translations.html">translations of
412  <q>free software</q></a> into various languages.  &ldquo;free software&rdquo;</a> into various languages.
413  </p>  </p>
414    
415    <h4>How we interpret these criteria</h4>
416    
417  <p>  <p>
418  Finally, note that criteria such as those stated in this free software  Finally, note that criteria such as those stated in this free software
419  definition require careful thought for their interpretation.  To decide  definition require careful thought for their interpretation.  To decide
# Line 222  a conclusion about a new issue, we often Line 428  a conclusion about a new issue, we often
428  it easier to see why certain licenses do or don't qualify.  it easier to see why certain licenses do or don't qualify.
429  </p>  </p>
430    
431    <h4>Get help with free licenses</h4>
432    
433  <p>  <p>
434  If you are interested in whether a specific license qualifies as a free  If you are interested in whether a specific license qualifies as a free
435  software license, see our <a href="/licenses/license-list.html">list  software license, see our <a href="/licenses/license-list.html">list
# Line 231  listed there, you can ask us about it by Line 439  listed there, you can ask us about it by
439  </p>  </p>
440    
441  <p>  <p>
442  If you are contemplating writing a new license, please contact the FSF  If you are contemplating writing a new license, please contact the
443  by writing to that address. The proliferation of different free software  Free Software Foundation first by writing to that address. The
444  licenses means increased work for users in understanding the licenses;  proliferation of different free software licenses means increased work
445  we may be able to help you find an existing Free Software license that  for users in understanding the licenses; we may be able to help you
446  meets your needs.  find an existing free software license that meets your needs.
447  </p>  </p>
448    
449  <p>  <p>
450  If that isn't possible, if you really need a new license, with our  If that isn't possible, if you really need a new license, with our
451  help you can ensure that the license really is a Free Software license  help you can ensure that the license really is a free software license
452  and avoid various practical problems.  and avoid various practical problems.
453  </p>  </p>
454    
455  <h2 id="beyond-software">Beyond Software</h2>  <h3 id="beyond-software">Beyond Software</h3>
456    
457  <p>  <p>
458  <a href="/philosophy/free-doc.html">Software manuals must be free</a>,  <a href="/philosophy/free-doc.html">Software manuals must be free</a>,
# Line 256  manuals are in effect part of the softwa Line 464  manuals are in effect part of the softwa
464  The same arguments also make sense for other kinds of works of  The same arguments also make sense for other kinds of works of
465  practical use &mdash; that is to say, works that embody useful knowledge,  practical use &mdash; that is to say, works that embody useful knowledge,
466  such as educational works and reference  such as educational works and reference
467  works.  <a href="http://wikipedia.org">Wikipedia</a> is the best known  works.  <a href="http://wikipedia.org">Wikipedia</a> is the best-known
468  example.  example.
469  </p>  </p>
470    
# Line 266  has been extended to a definition of <a Line 474  has been extended to a definition of <a
474  free cultural works</a> applicable to any kind of works.  free cultural works</a> applicable to any kind of works.
475  </p>  </p>
476    
477  <h2 id="open-source">Open Source?</h2>  <h3 id="open-source">Open Source?</h3>
478    
479  <p>  <p>
480  Another group has started using the term <q>open source</q> to mean  Another group uses the term &ldquo;open source&rdquo; to mean
481  something close (but not identical) to <q>free software.</q>  We  something close (but not identical) to &ldquo;free software&rdquo;.  We
482  prefer the term <q>free software</q> because, once you have heard that  prefer the term &ldquo;free software&rdquo; because, once you have heard that
483  it refers to freedom rather than price, it calls to mind freedom.  The  it refers to freedom rather than price, it calls to mind freedom.  The
484  word <q>open</q> <a href="/philosophy/open-source-misses-the-point.html">  word &ldquo;open&rdquo; <a href="/philosophy/open-source-misses-the-point.html">
485  never refers to freedom</a>.  never refers to freedom</a>.
486  </p>  </p>
487    </div>
488    
489  <h2 id="History">History</h2>  <h3 id="History">History</h3>
490    
491  <p>From time to time we revise this Free Software Definition to  <p>From time to time we revise this Free Software Definition.  Here is
492  clarify it.  Here we provide a list of those modifications, along with  the list of substantive changes, along with links to show exactly what
493  links to illustrate exactly what changed, so that others can review  was changed.</p>
 them if they like.</p>  
494    
495  <ul>  <ul>
496    
497    <li><a href="http://web.cvs.savannah.gnu.org/viewvc/www/philosophy/free-sw.html?root=www&amp;r1=1.168&amp;r2=1.169">Version
498    1.169</a>: Explain why more clearly why the four freedoms must apply
499    to commercial activity.  Explain why the four freedoms imply the
500    freedom not to run the program and the freedom to delete it, so there
501    is no need to state those as separate requirements.</li>
502    
503    <li><a href="http://web.cvs.savannah.gnu.org/viewvc/www/philosophy/free-sw.html?root=www&amp;r1=1.164&amp;r2=1.165">Version
504    1.165</a>: Clarify that arbitrary annoyances in the code do not
505    negate freedom 0, and that freedoms 1 and 3 enable users to remove them.</li>
506    
507    <li><a href="http://web.cvs.savannah.gnu.org/viewvc/www/philosophy/free-sw.html?root=www&amp;r1=1.152&amp;r2=1.153">Version
508    1.153</a>: Clarify that freedom to run the program means nothing stops
509    you from making it run.</li>
510    
511    <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
512    1.141</a>: Clarify which code needs to be free.</li>
513    
514    <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
515    1.135</a>: Say each time that freedom 0 is the freedom to run the program
516    as you wish.</li>
517    
518    <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
519    1.134</a>: Freedom 0 is not a matter of the program's functionality.</li>
520    
521    <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
522    1.131</a>: A free license may not require compliance with a nonfree license
523    of another program.</li>
524    
525    <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
526    1.129</a>: State explicitly that choice of law and choice of forum
527    specifications are allowed.  (This was always our policy.)</li>
528    
529    <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
530    1.122</a>: An export control requirement is a real problem if the
531    requirement is nontrivial; otherwise it is only a potential problem.</li>
532    
533    <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
534    1.118</a>: Clarification: the issue is limits on your right to modify,
535    not on what modifications you have made.  And modifications are not limited
536    to &ldquo;improvements&rdquo;</li>
537    
538    <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
539    1.111</a>: Clarify 1.77 by saying that only
540    retroactive <em>restrictions</em> are unacceptable.  The copyright
541    holders can always grant additional <em>permission</em> for use of the
542    work by releasing the work in another way in parallel.</li>
543    
544    <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
545    1.105</a>: Reflect, in the brief statement of freedom 1, the point
546    (already stated in version 1.80) that it includes really using your modified
547    version for your computing.</li>
548    
549    <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
550    1.92</a>: Clarify that obfuscated code does not qualify as source code.</li>
551    
552    <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
553    1.90</a>: Clarify that freedom 3 means the right to distribute copies
554    of your own modified or improved version, not a right to participate
555    in someone else's development project.</li>
556    
557    <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
558    1.89</a>: Freedom 3 includes the right to release modified versions as
559    free software.</li>
560    
561    <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
562    1.80</a>: Freedom 1 must be practical, not just theoretical;
563    i.e., no tivoization.</li>
564    
565    <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
566    1.77</a>: Clarify that all retroactive changes to the license are
567    unacceptable, even if it's not described as a complete
568    replacement.</li>
569    
570  <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  <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
571  1.74</a>: Four clarifications of points not explicit enough, or stated  1.74</a>: Four clarifications of points not explicit enough, or stated
572  in some places but not reflected everywhere:  in some places but not reflected everywhere:
# Line 333  licenses.</li> Line 614  licenses.</li>
614    
615  <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  <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
616  1.11</a>: Note that a free license may require you to send a copy of  1.11</a>: Note that a free license may require you to send a copy of
617  versions you distribute to the author.</li>  versions you distribute to previous developers on request.</li>
618    
619  </ul>  </ul>
620    
621  <p>There are gaps in the version numbers because there are many other  <p>There are gaps in the version numbers shown above because there are
622  changes that do not affect the substance of the definition at all.  other changes in this page that do not affect the definition or its
623  Instead, they fix links, add translations, and so on.  If you would  interpretations.  For instance, the list does not include changes in
624  like to review the complete list of changes, you can do so on  asides, formatting, spelling, punctuation, or other parts of the page.
625  our <a href="http://web.cvs.savannah.gnu.org/viewvc/www/philosophy/free-sw.html?root=www&amp;view=log">cvsweb  You can review the complete list of changes to the page through
626    the <a href="http://web.cvs.savannah.gnu.org/viewvc/www/philosophy/free-sw.html?root=www&amp;view=log">cvsweb
627  interface</a>.</p>  interface</a>.</p>
628    
629  </div>  <h3 style="font-size:1em">Footnote</h3>
630    <ol>
631    <li id="f1">The reason they are numbered 0, 1, 2 and 3 is historical. Around
632    1990 there were three freedoms, numbered 1, 2 and 3. Then we realized that
633    the freedom to run the program needed to be mentioned explicitly.
634    It was clearly more basic than the other three, so it properly should
635    precede them. Rather than renumber the others, we made it freedom&nbsp;0.</li>
636    </ol>
637    
638    </div><!-- for id="content", starts in the include above -->
639  <!--#include virtual="/server/footer.html" -->  <!--#include virtual="/server/footer.html" -->
   
640  <div id="footer">  <div id="footer">
641    <div class="unprintable">
642    
643  <p>  <p>Please send general FSF &amp; GNU inquiries to
644  Please send FSF &amp; GNU inquiries to  <a href="mailto:gnu@gnu.org">&lt;gnu@gnu.org&gt;</a>.
645  <a href="mailto:gnu@gnu.org"><em>gnu@gnu.org</em></a>.  There are also <a href="/contact/">other ways to contact</a>
646  There are also <a href="/contact/">other ways to contact</a>  the FSF.  Broken links and other corrections or suggestions can be sent
647  the FSF.  to <a href="mailto:webmasters@gnu.org">&lt;webmasters@gnu.org&gt;</a>.</p>
648  <br />  
649  Please send broken links and other corrections or suggestions to  <p><!-- TRANSLATORS: Ignore the original text in this paragraph,
650  <a href="mailto:webmasters@gnu.org"><em>webmasters@gnu.org</em></a>.          replace it with the translation of these two:
651  </p>  
652            We work hard and do our best to provide accurate, good quality
653            translations.  However, we are not exempt from imperfection.
654            Please send your comments and general suggestions in this regard
655            to <a href="mailto:web-translators@gnu.org">
656            &lt;web-translators@gnu.org&gt;</a>.</p>
657    
658            <p>For information on coordinating and submitting translations of
659            our web pages, see <a
660            href="/server/standards/README.translations.html">Translations
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662    Please see the <a
663    href="/server/standards/README.translations.html">Translations
664    README</a> for information on coordinating and submitting translations
665    of this article.</p>
666    </div>
667    
668  <p>  <!-- Regarding copyright, in general, standalone pages (as opposed to
669  Please see the       files generated as part of manuals) on the GNU web server should
670  <a href="/server/standards/README.translations.html">Translations       be under CC BY-ND 4.0.  Please do NOT change or remove this
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672  translations of this article.       Please make sure the copyright date is consistent with the
673  </p>       document.  For web pages, it is ok to list just the latest year the
674         document was modified, or published.
675        
676         If you wish to list earlier years, that is ok too.
677         Either "2001, 2002, 2003" or "2001-2003" are ok for specifying
678         years, as long as each year in the range is in fact a copyrightable
679         year, i.e., a year in which the document was published (including
680         being publicly visible on the web or in a revision control system).
681        
682         There is more detail about copyright years in the GNU Maintainers
683         Information document, www.gnu.org/prep/maintain. -->
684    
685    <p>Copyright &copy; 1996, 2002, 2004-2007, 2009-2019
686    Free Software Foundation, Inc.</p>
687    
688    <p>This page is licensed under a <a rel="license"
689    href="http://creativecommons.org/licenses/by-nd/4.0/">Creative
690    Commons Attribution-NoDerivatives 4.0 International License</a>.</p>
691    
692  <p>  <!--#include virtual="/server/bottom-notes.html" -->
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 2005, 2006, 2007 Free Software Foundation, Inc.,  
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 </p>  
693    
694  <p>  <p class="unprintable">Updated:
 Updated:  
695  <!-- timestamp start -->  <!-- timestamp start -->
696  $Date$  $Date$
697  <!-- timestamp end -->  <!-- timestamp end -->
698  </p>  </p>
699  </div>  </div>
700    </div><!-- for class="inner", starts in the banner include -->
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 <li><a href="/philosophy/free-sw.af.html">Afrikaans</a>&nbsp;[af]</li>  
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 <li><a href="/philosophy/free-sw.ar.html">&#1575;&#1604;&#1593;&#1585;&#1576;&#1610;&#1577;</a>&nbsp;[ar]</li>  
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 <li><a href="/philosophy/free-sw.bn.html">&#2476;&#2494;&#2434;&#2482;&#2494;</a>&nbsp;[bn]</li>  
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