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4    - GNU Project - Free Software Foundation</title>
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16    
17  <h1>The Free Software Definition</h1>  <h2>What is free software?</h2>
18    
19  <p>  <div class="article">
20  We maintain this free software definition to show clearly what must  <h3>The Free Software Definition</h3>
21  be true about a particular software program for it to be considered  
22  free software.  <blockquote class="note" id="fsf-licensing"><p style="font-size: 80%">
23    Have a question about free software licensing not answered here?
24    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        to the public, so that the whole community benefits (freedom 3).        to others (freedom 3).  By doing this you can give the whole
92          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;.  A free
113    program must be available for commercial use, commercial development,
114    and commercial distribution.  Commercial development of free software
115    is no longer unusual; such free commercial software is very important.
116    You may have paid money to get copies of free software, or you may have
117    obtained copies at no charge.  But regardless of how you got your copies,
118    you always have the freedom to copy and change the software, even to
119    <a href="/philosophy/selling.html">sell copies</a>.
120  </p>  </p>
121    
122  <p>  <p>
123  You should also have the freedom to make modifications and use them  A free program must offer the four freedoms to any user that obtains a
124  privately in your own work or play, without even mentioning that they  copy of the software, provided the user has complied thus far with the
125  exist.  If you do publish your changes, you should not be required to  conditions of the free license covering the software.  Putting some of
126  notify anyone in particular, or in any particular way.  the freedoms off limits to some users, or requiring that users pay, in
127    money or in kind, to exercise them, is tantamount to not granting the
128    freedoms in question, and thus renders the program nonfree.
129  </p>  </p>
130    
131    <p>The rest of this page clarifies certain points about what makes
132    specific freedoms adequate or not.</p>
133    
134    <h4>The freedom to run the program as you wish</h4>
135    
136  <p>  <p>
137  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
138  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
139  overall job and purpose, without being required to communicate about it  overall job and purpose, without being required to communicate about it
140  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
141  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>
142  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,
143  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
144  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.
145  </p>  </p>
146    
147  <p>  <p>
148  The freedom to redistribute copies must include binary or executable  The freedom to run the program as you wish means that you are not
149  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
150  unmodified versions.  (Distributing programs in runnable form is necessary  functionality the program has, whether it is technically capable of
151  for conveniently installable free operating systems.)  It is ok if there  functioning in any given environment, or whether it is useful for any
152  is no way to produce a binary or executable form for a certain program  particular computing activity.</p>
153  (since some languages don't support that feature), but you must have the  
154  freedom to redistribute such forms should you find or develop a way to  <h4>The freedom to study the source code and make changes</h4>
155  make them.  
156    <p>
157    In order for freedoms 1 and 3 (the freedom to make changes and the
158    freedom to publish the changed versions) to be meaningful, you must have
159    access to the source code of the program.  Therefore, accessibility of
160    source code is a necessary condition for free software.  Obfuscated
161    &ldquo;source code&rdquo; is not real source code and does not count
162    as source code.
163  </p>  </p>
164    
165  <p>  <p>
166  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
167  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
168  the program.  Therefore, accessibility of source code is a necessary  run someone else's modified versions but refuse to run yours &mdash; a
169  condition for free software.  practice known as &ldquo;tivoization&rdquo; or &ldquo;lockdown&rdquo;,
170    or (in its practitioners' perverse terminology) as &ldquo;secure
171    boot&rdquo; &mdash; freedom 1 becomes an empty pretense rather than a
172    practical reality.  These binaries are not free
173    software even if the source code they are compiled from is free.
174  </p>  </p>
175    
176  <p>  <p>
177  One important way to modify a program is by merging in available  One important way to modify a program is by merging in available free
178  free subroutines and modules.  If the program's license says that you  subroutines and modules.  If the program's license says that you
179  cannot merge in an existing module, such as if it requires you to be the  cannot merge in a suitably licensed existing module &mdash; for instance, if it
180  copyright holder of any code you add, then the license is too restrictive  requires you to be the copyright holder of any code you add &mdash; then the
181  to qualify as free.  license is too restrictive to qualify as free.
182  </p>  </p>
183    
184  <p>  <p>
185  In order for these freedoms to be real, they must be irrevocable as  Whether a change constitutes an improvement is a subjective matter.
186  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
187  power to revoke the license, without your doing anything to give cause,  someone else considers an improvement, that program is not free.
188  the software is not free.  </p>
189    
190    <h4>The freedom to redistribute if you wish: basic requirements</h4>
191    
192    <p>Freedom to distribute (freedoms 2 and 3) means you are free to
193    redistribute copies, either with or without modifications, either
194    gratis or charging a fee for distribution, to
195    <a href="#exportcontrol">anyone anywhere</a>.  Being free to do these
196    things means (among other things) that you do not have to ask or pay
197    for permission to do so.
198  </p>  </p>
199    
200  <p>  <p>
201  However, certain kinds of rules about the manner of distributing free  You should also have the freedom to make modifications and use them
202  software are acceptable, when they don't conflict with the central  privately in your own work or play, without even mentioning that they
203  freedoms.  For example, copyleft (very simply stated) is the rule that  exist.  If you do publish your changes, you should not be required to
204  when redistributing the program, you cannot add restrictions to deny  notify anyone in particular, or in any particular way.
 other people the central freedoms.  This rule does not conflict with  
 the central freedoms; rather it protects them.  
205  </p>  </p>
206    
207  <p>  <p>
208  You may have paid money to get copies of free software, or you may have  Freedom 3 includes the freedom to release your modified versions
209  obtained copies at no charge.  But regardless of how you got your copies,  as free software.  A free license may also permit other ways of
210  you always have the freedom to copy and change the software, even to  releasing them; in other words, it does not have to be
211  <a href="/philosophy/selling.html">sell copies</a>.  a <a href="/copyleft/copyleft.html">copyleft</a> license.  However, a
212    license that requires modified versions to be nonfree does not qualify
213    as a free license.
214  </p>  </p>
215    
216  <p>  <p>
217  <q>Free software</q> does not mean <q>non-commercial.</q>  A free  The freedom to redistribute copies must include binary or executable
218  program must be available for commercial use, commercial development,  forms of the program, as well as source code, for both modified and
219  and commercial distribution.  Commercial development of free software  unmodified versions.  (Distributing programs in runnable form is necessary
220  is no longer unusual; such free commercial software is very important.  for conveniently installable free operating systems.)  It is OK if there
221    is no way to produce a binary or executable form for a certain program
222    (since some languages don't support that feature), but you must have the
223    freedom to redistribute such forms should you find or develop a way to
224    make them.
225  </p>  </p>
226    
227    <h4>Copyleft</h4>
228    
229  <p>  <p>
230  Rules about how to package a modified version are acceptable, if they  Certain kinds of rules about the manner of distributing free
231  don't substantively block your freedom to release modified versions, or  software are acceptable, when they don't conflict with the central
232  your freedom to make and use modified versions privately.  Rules that <q>if  freedoms.  For example, <a href="/copyleft/copyleft.html">copyleft</a>
233  you make your version available in this way, you must make it available in  (very simply stated) is the rule that when redistributing the program,
234  that way also</q> can be acceptable too, on the same condition.  (Note that  you cannot add restrictions to deny other people the central freedoms.
235  such a rule still leaves you the choice of whether to publish your version  This rule does not conflict with the central freedoms; rather it
236  at all.)  Rules that require release of source code to the users for  protects them.
237  versions that you put into public use are also acceptable.  It is also  </p>
238  acceptable for the license to require that, if you have distributed a  
239  modified version and a previous developer asks for a copy of it, you  <p>
240  must send one, or that you identify yourself on your modifications.  In the GNU project, we use copyleft to protect the four freedoms
241    legally for everyone.  We believe there are important reasons why
242    <a href="/philosophy/pragmatic.html">it is better to use
243    copyleft</a>.  However,
244    <a href="/philosophy/categories.html#Non-CopyleftedFreeSoftware">
245    noncopylefted free software</a> is ethical
246    too.  See <a href="/philosophy/categories.html">Categories of Free
247    Software</a> for a description of how &ldquo;free software,&rdquo;
248    &ldquo;copylefted software&rdquo; and other categories of software
249    relate to each other.
250  </p>  </p>
251    
252    <h4>Rules about packaging and distribution details</h4>
253    
254  <p>  <p>
255  In the GNU project, we use  Rules about how to package a modified version are acceptable,
256  <q><a href="/copyleft/copyleft.html">copyleft</a></q>  if they don't substantively limit your freedom to release modified
257  to protect these freedoms legally for everyone.  But  versions, or your freedom to make and use modified versions privately.
258  <a href="/philosophy/categories.html#Non-CopyleftedFreeSoftware">non-copylefted  Thus, it is acceptable for the license to require that you change the
259  free software</a> also exists.  We believe there are important reasons why  name of the modified version, remove a logo, or identify your
260  <a href="/philosophy/pragmatic.html"> it is better to use copyleft</a>,  modifications as yours.  As long as these requirements are not so
261  but if your program is non-copylefted free software, we can still  burdensome that they effectively hamper you from releasing your
262  use it.  changes, they are acceptable; you're already making other changes to
263    the program, so you won't have trouble making a few more.
264  </p>  </p>
265    
266  <p>  <p>
267  See <a href="/philosophy/categories.html">Categories of Free Software</a>  Rules that &ldquo;if you make your version available in this way, you
268  for a description of how <q>free software,</q> <q>copylefted software</q>  must make it available in that way also&rdquo; can be acceptable too,
269  and other categories of software relate to each other.  on the same condition.  An example of such an acceptable rule is one
270    saying that if you have distributed a
271    modified version and a previous developer asks for a copy of it, you
272    must send one.  (Note that such a rule still leaves you the choice of
273    whether to distribute your version at all.)  Rules that require release
274    of source code to the users for versions that you put into public use
275    are also acceptable.
276  </p>  </p>
277    
278  <p>  <p>
279    A special issue arises when a license requires changing the name by
280    which the program will be invoked from other programs.  That
281    effectively hampers you from releasing your changed version so that it
282    can replace the original when invoked by those other programs.  This
283    sort of requirement is acceptable only if there's a suitable aliasing
284    facility that allows you to specify the original program's name as an
285    alias for the modified version.</p>
286    
287    <h4>Export regulations</h4>
288    
289    <p>
290  Sometimes government <a id="exportcontrol">export control regulations</a>  Sometimes government <a id="exportcontrol">export control regulations</a>
291  and trade sanctions can constrain your freedom to distribute copies of  and trade sanctions can constrain your freedom to distribute copies of
292  programs internationally.  Software developers do not have the power to  programs internationally.  Software developers do not have the power to
293  eliminate or override these restrictions, but what they can and must do  eliminate or override these restrictions, but what they can and must do
294  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
295  way, the restrictions will not affect activities and people outside the  way, the restrictions will not affect activities and people outside the
296  jurisdictions of these governments.  jurisdictions of these governments.  Thus, free software licenses
297    must not require obedience to any nontrivial export regulations as a
298    condition of exercising any of the essential freedoms.
299    </p>
300    
301    <p>
302    Merely mentioning the existence of export regulations, without making
303    them a condition of the license itself, is acceptable since it does
304    not restrict users.  If an export regulation is actually trivial for
305    free software, then requiring it as a condition is not an actual
306    problem; however, it is a potential problem, since a later change in
307    export law could make the requirement nontrivial and thus render the
308    software nonfree.
309    </p>
310    
311    <h4>Legal considerations</h4>
312    
313    <p>
314    In order for these freedoms to be real, they must be permanent and
315    irrevocable as long as you do nothing wrong; if the developer of the
316    software has the power to revoke the license, or retroactively add
317    restrictions to its terms, without your doing anything wrong to give
318    cause, the software is not free.
319    </p>
320    
321    <p>
322    A free license may not require compliance with the license of a
323    nonfree program.  Thus, for instance, if a license requires you to
324    comply with the licenses of &ldquo;all the programs you use&rdquo;, in
325    the case of a user that runs nonfree programs this would require
326    compliance with the licenses of those nonfree programs; that makes the
327    license nonfree.
328  </p>  </p>
329    
330  <p>  <p>
331    It is acceptable for a free license to specify which jurisdiction's
332    law applies, or where litigation must be done, or both.
333    </p>
334    
335    <h4>Contract-based licenses</h4>
336    
337    <p>
338  Most free software licenses are based on copyright, and there are limits  Most free software licenses are based on copyright, and there are limits
339  on what kinds of requirements can be imposed through copyright.  If a  on what kinds of requirements can be imposed through copyright.  If a
340  copyright-based license respects freedom in the ways described above, it  copyright-based license respects freedom in the ways described above, it
# Line 176  is unlikely to have some other sort of p Line 342  is unlikely to have some other sort of p
342  (though this does happen occasionally).  However, some free software  (though this does happen occasionally).  However, some free software
343  licenses are based on contracts, and contracts can impose a much larger  licenses are based on contracts, and contracts can impose a much larger
344  range of possible restrictions.  That means there are many possible ways  range of possible restrictions.  That means there are many possible ways
345  such a license could be unacceptably restrictive and non-free.  such a license could be unacceptably restrictive and nonfree.
346  </p>  </p>
347    
348  <p>  <p>
# Line 184  We can't possibly list all the ways that Line 350  We can't possibly list all the ways that
350  contract-based license restricts the user in an unusual way that  contract-based license restricts the user in an unusual way that
351  copyright-based licenses cannot, and which isn't mentioned here as  copyright-based licenses cannot, and which isn't mentioned here as
352  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
353  it is non-free.  it is nonfree.
354  </p>  </p>
355    
356    <h4>Use the right words when talking about free software</h4>
357    
358  <p>  <p>
359  When talking about free software, it is best to avoid using terms  When talking about free software, it is best to avoid using terms
360  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
361  the issue is about price, not freedom.  Some common terms such  the issue is about price, not freedom.  Some common terms such
362  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
363  <a href="/philosophy/words-to-avoid.html">Confusing Words and Phrases that  <a href="/philosophy/words-to-avoid.html">Confusing Words and Phrases that
364  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
365  a list of <a href="/philosophy/fs-translations.html">translations of  a list of proper <a href="/philosophy/fs-translations.html">translations of
366  <q>free software</q></a> into various languages.  &ldquo;free software&rdquo;</a> into various languages.
367  </p>  </p>
368    
369    <h4>How we interpret these criteria</h4>
370    
371  <p>  <p>
372  Finally, note that criteria such as those stated in this free software  Finally, note that criteria such as those stated in this free software
373  definition require careful thought for their interpretation.  To decide  definition require careful thought for their interpretation.  To decide
# Line 212  a conclusion about a new issue, we often Line 382  a conclusion about a new issue, we often
382  it easier to see why certain licenses do or don't qualify.  it easier to see why certain licenses do or don't qualify.
383  </p>  </p>
384    
385    <h4>Get help with free licenses</h4>
386    
387  <p>  <p>
388  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
389  software license, see our <a href="/licenses/license-list.html">list  software license, see our <a href="/licenses/license-list.html">list
# Line 221  listed there, you can ask us about it by Line 393  listed there, you can ask us about it by
393  </p>  </p>
394    
395  <p>  <p>
396  If you are contemplating writing a new license, please contact the FSF  If you are contemplating writing a new license, please contact the
397  by writing to that address. The proliferation of different free software  Free Software Foundation first by writing to that address. The
398  licenses means increased work for users in understanding the licenses;  proliferation of different free software licenses means increased work
399  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
400  meets your needs.  find an existing free software license that meets your needs.
401  </p>  </p>
402    
403  <p>  <p>
404  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
405  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
406  and avoid various practical problems.  and avoid various practical problems.
407  </p>  </p>
408    
409  <h2 id="open-source">Beyond Software</h2>  <h3 id="beyond-software">Beyond Software</h3>
410    
411  <p>  <p>
412  <a href="free-doc.html">Software manuals must be free</a>, for the same  <a href="/philosophy/free-doc.html">Software manuals must be free</a>,
413  reasons that software must be free, and because the manuals are in effect  for the same reasons that software must be free, and because the
414  part of the software.</p>  manuals are in effect part of the software.
415  </p>  </p>
416    
417  <p>  <p>
418  The same arguments also make sense for other kinds of works of  The same arguments also make sense for other kinds of works of
419  practical use -- that is to say, works that embody useful knowledge,  practical use &mdash; that is to say, works that embody useful knowledge,
420  such as educational works and reference  such as educational works and reference
421  works.  <a href="http://wikipedia.org"> Wikipedia </a> is the best known  works.  <a href="http://wikipedia.org">Wikipedia</a> is the best-known
422  example.  example.
423  </p>  </p>
424    
# Line 256  has been extended to a definition of <a Line 428  has been extended to a definition of <a
428  free cultural works</a> applicable to any kind of works.  free cultural works</a> applicable to any kind of works.
429  </p>  </p>
430    
431  <h2 id="open-source">Open Source?</h2>  <h3 id="open-source">Open Source?</h3>
432    
433  <p>  <p>
434  Another group has started using the term <q>open source</q> to mean  Another group uses the term &ldquo;open source&rdquo; to mean
435  something close (but not identical) to <q>free software.</q>  We  something close (but not identical) to &ldquo;free software&rdquo;.  We
436  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
437  it refers to freedom rather than price, it calls to mind freedom.  it refers to freedom rather than price, it calls to mind freedom.  The
438  The word <q>open</q> <a href="open-source-misses-the-point.html">  word &ldquo;open&rdquo; <a href="/philosophy/open-source-misses-the-point.html">
439  never refers to freedom </a>.  never refers to freedom</a>.
440  </p>  </p>
441    </div>
442    
443  <p><a href="/philosophy/philosophy.html">Other Texts to Read</a></p>  <h3 id="History">History</h3>
444    
445  </div>  <p>From time to time we revise this Free Software Definition.  Here is
446    the list of substantive changes, along with links to show exactly what
447    was changed.</p>
448    
449    <ul>
450    
451  <!--#include virtual="/server/footer.html" -->  <li><a href="http://web.cvs.savannah.gnu.org/viewvc/www/philosophy/free-sw.html?root=www&amp;r1=1.162&amp;r2=1.163">Version
452    1.163</a>: Clarify that the four freedoms apply to any and all users,
453    and that requiring users to pay to exercise some of these freedoms is
454    a way of denying them.</li>
455    
456    <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
457    1.153</a>: Clarify that freedom to run the program means nothing stops
458    you from making it run.</li>
459    
460    <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
461    1.141</a>: Clarify which code needs to be free.</li>
462    
463    <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
464    1.135</a>: Say each time that freedom 0 is the freedom to run the program
465    as you wish.</li>
466    
467    <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
468    1.134</a>: Freedom 0 is not a matter of the program's functionality.</li>
469    
470    <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
471    1.131</a>: A free license may not require compliance with a nonfree license
472    of another program.</li>
473    
474    <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
475    1.129</a>: State explicitly that choice of law and choice of forum
476    specifications are allowed.  (This was always our policy.)</li>
477    
478    <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
479    1.122</a>: An export control requirement is a real problem if the
480    requirement is nontrivial; otherwise it is only a potential problem.</li>
481    
482    <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
483    1.118</a>: Clarification: the issue is limits on your right to modify,
484    not on what modifications you have made.  And modifications are not limited
485    to &ldquo;improvements&rdquo;</li>
486    
487    <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
488    1.111</a>: Clarify 1.77 by saying that only
489    retroactive <em>restrictions</em> are unacceptable.  The copyright
490    holders can always grant additional <em>permission</em> for use of the
491    work by releasing the work in another way in parallel.</li>
492    
493    <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
494    1.105</a>: Reflect, in the brief statement of freedom 1, the point
495    (already stated in version 1.80) that it includes really using your modified
496    version for your computing.</li>
497    
498    <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
499    1.92</a>: Clarify that obfuscated code does not qualify as source code.</li>
500    
501    <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
502    1.90</a>: Clarify that freedom 3 means the right to distribute copies
503    of your own modified or improved version, not a right to participate
504    in someone else's development project.</li>
505    
506    <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
507    1.89</a>: Freedom 3 includes the right to release modified versions as
508    free software.</li>
509    
510    <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
511    1.80</a>: Freedom 1 must be practical, not just theoretical;
512    i.e., no tivoization.</li>
513    
514    <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
515    1.77</a>: Clarify that all retroactive changes to the license are
516    unacceptable, even if it's not described as a complete
517    replacement.</li>
518    
519    <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
520    1.74</a>: Four clarifications of points not explicit enough, or stated
521    in some places but not reflected everywhere:
522    <ul>
523    <li>"Improvements" does not mean the license can
524    substantively limit what kinds of modified versions you can release.
525    Freedom 3 includes distributing modified versions, not just changes.</li>
526    <li>The right to merge in existing modules
527    refers to those that are suitably licensed.</li>
528    <li>Explicitly state the conclusion of the point about export controls.</li>
529    <li>Imposing a license change constitutes revoking the old license.</li>
530    </ul>
531    </li>
532    
533  <div id="footer">  <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
534    1.57</a>: Add &quot;Beyond Software&quot; section.</li>
535    
536  <p>  <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
537  Please send FSF &amp; GNU inquiries to  1.46</a>: Clarify whose purpose is significant in the freedom to run
538  <a href="mailto:gnu@gnu.org"><em>gnu@gnu.org</em></a>.  the program for any purpose.</li>
539  There are also <a href="http://www.fsf.org/about/contact.html">other ways to contact</a>  
540  the FSF.  <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
541  <br />  1.41</a>: Clarify wording about contract-based licenses.</li>
542  Please send broken links and other corrections (or suggestions) to  
543  <a href="mailto:webmasters@gnu.org"><em>webmasters@gnu.org</em></a>.  <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
544  </p>  1.40</a>: Explain that a free license must allow to you use other
545    available free software to create your modifications.</li>
546    
547    <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
548    1.39</a>: Note that it is acceptable for a license to require you to
549    provide source for versions of the software you put into public
550    use.</li>
551    
552    <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
553    1.31</a>: Note that it is acceptable for a license to require you to
554    identify yourself as the author of modifications.  Other minor
555    clarifications throughout the text.</li>
556    
557    <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
558    1.23</a>: Address potential problems related to contract-based
559    licenses.</li>
560    
561    <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
562    1.16</a>: Explain why distribution of binaries is important.</li>
563    
564    <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
565    1.11</a>: Note that a free license may require you to send a copy of
566    versions you distribute to previous developers on request.</li>
567    
568  <p>  </ul>
 Please see the  
 <a href="/server/standards/README.translations.html">Translations  
 README</a> for information on coordinating and submitting  
 translations of this article.  
 </p>  
569    
570  <p>  <p>There are gaps in the version numbers shown above because there are
571  Copyright (C) 1996, 1997, 1998, 1999, 2000, 2001, 2002, 2003, 2004,  other changes in this page that do not affect the definition or its
572  2005, 2006 <br /> Free Software Foundation, Inc., 51 Franklin St,  interpretations.  For instance, the list does not include changes in
573  Fifth Floor, Boston, MA 02110-1301,  USA  asides, formatting, spelling, punctuation, or other parts of the page.
574  <br />  You can review the complete list of changes to the page through
575  Verbatim copying and distribution of this entire article is  the <a href="http://web.cvs.savannah.gnu.org/viewvc/www/philosophy/free-sw.html?root=www&amp;view=log">cvsweb
576  permitted in any medium without royalty provided this notice is  interface</a>.</p>
577  preserved.  
578  </p>  <h3 style="font-size:1em">Footnote</h3>
579    <ol>
580    <li id="f1">The reason they are numbered 0, 1, 2 and 3 is historical. Around
581    1990 there were three freedoms, numbered 1, 2 and 3. Then we realized that
582    the freedom to run the program needed to be mentioned explicitly.
583    It was clearly more basic than the other three, so it properly should
584    precede them. Rather than renumber the others, we made it freedom&nbsp;0.</li>
585    </ol>
586    
587  <p>  </div><!-- for id="content", starts in the include above -->
588  Updated:  <!--#include virtual="/server/footer.html" -->
589  <!-- timestamp start -->  <div id="footer">
590  $Date$ $Author$  <div class="unprintable">
591  <!-- timestamp end -->  
592  </p>  <p>Please send general FSF &amp; GNU inquiries to
593    <a href="mailto:gnu@gnu.org">&lt;gnu@gnu.org&gt;</a>.
594    There are also <a href="/contact/">other ways to contact</a>
595    the FSF.  Broken links and other corrections or suggestions can be sent
596    to <a href="mailto:webmasters@gnu.org">&lt;webmasters@gnu.org&gt;</a>.</p>
597    
598    <p><!-- TRANSLATORS: Ignore the original text in this paragraph,
599            replace it with the translation of these two:
600    
601            We work hard and do our best to provide accurate, good quality
602            translations.  However, we are not exempt from imperfection.
603            Please send your comments and general suggestions in this regard
604            to <a href="mailto:web-translators@gnu.org">
605            &lt;web-translators@gnu.org&gt;</a>.</p>
606    
607            <p>For information on coordinating and submitting translations of
608            our web pages, see <a
609            href="/server/standards/README.translations.html">Translations
610            README</a>. -->
611    Please see the <a
612    href="/server/standards/README.translations.html">Translations
613    README</a> for information on coordinating and submitting translations
614    of this article.</p>
615  </div>  </div>
616    
617  <div id="translations">  <!-- Regarding copyright, in general, standalone pages (as opposed to
618  <h4>Translations of this page</h4>       files generated as part of manuals) on the GNU web server should
619         be under CC BY-ND 4.0.  Please do NOT change or remove this
620         without talking with the webmasters or licensing team first.
621         Please make sure the copyright date is consistent with the
622         document.  For web pages, it is ok to list just the latest year the
623         document was modified, or published.
624        
625         If you wish to list earlier years, that is ok too.
626         Either "2001, 2002, 2003" or "2001-2003" are ok for specifying
627         years, as long as each year in the range is in fact a copyrightable
628         year, i.e., a year in which the document was published (including
629         being publicly visible on the web or in a revision control system).
630        
631         There is more detail about copyright years in the GNU Maintainers
632         Information document, www.gnu.org/prep/maintain. -->
633    
634    <p>Copyright &copy; 1996, 2002, 2004-2007, 2009-2019
635    Free Software Foundation, Inc.</p>
636    
637    <p>This page is licensed under a <a rel="license"
638    href="http://creativecommons.org/licenses/by-nd/4.0/">Creative
639    Commons Attribution-NoDerivatives 4.0 International License</a>.</p>
640    
641  <!-- Please keep this list alphabetical, and in the original -->  <!--#include virtual="/server/bottom-notes.html" -->
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   <li><a href="/philosophy/free-sw.ar.html">&#1575;&#1604;&#1593;&#1585;&#1576;&#1610;&#1577;</a> <!-- Arabic --></li>  
  <li><a href="/philosophy/free-sw.bg.html">&#x431;&#x44A;&#x43B;&#x433;&#x430;&#x440;&#x441;&#x43A;&#x438;</a>  <!-- Bulgarian --></li>  
  <li><a href="/philosophy/free-sw.ca.html">Catal&#x00e0;</a>    <!-- Catalan --></li>  
   
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  <li><a href="/philosophy/free-sw.cn.html">&#x7b80;&#x4f53;&#x4e2d;&#x6587;</a></li>  
   
 <!-- Chinese (Traditional) -->  
  <li><a href="/philosophy/free-sw.zh.html">&#x7e41;&#x9ad4;&#x4e2d;&#x6587;</a></li>  
   
  <li><a href="/philosophy/free-sw.cs.html">&#x010c;esky</a>     <!-- Czech --></li>  
  <li><a href="/philosophy/free-sw.da.html">Dansk</a>    <!-- Danish --></li>  
  <li><a href="/philosophy/free-sw.de.html">Deutsch</a>  <!-- German --></li>  
  <li><a href="/philosophy/free-sw.html">English</a> </li>  
  <li><a href="/philosophy/free-sw.el.html">Ελληνικά</a>  <!--Greek--></li>  
  <li><a href="/philosophy/free-sw.es.html">Espa&#x00f1;ol</a>   <!-- Spanish --></li>  
  <li><a href="/philosophy/free-sw.eo.html">Esperanto</a></li>  
  <li><a href="/philosophy/free-sw.fa.html">&#x0641;&#x0627;&#x0631;&#x0633;&#x06cc;</a></li>  
  <li><a href="/philosophy/free-sw.fr.html">Fran&#x00e7;ais</a>  <!-- French --></li>  
  <li><a href="/philosophy/free-sw.gl.html">Galego</a>   <!-- Galician --></li>  
  <li><a href="/philosophy/free-sw.he.html">&#x05e2;&#x05d1;&#x05e8;&#x05d9;&#x05ea;</a> <!-- Hebrew --></li>  
  <li><a href="/philosophy/free-sw.hr.html">Hrvatski</a> <!-- Croatian --></li>  
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  <li><a href="/philosophy/free-sw.it.html">Italiano</a> <!-- Italian --></li>  
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  <li><a href="/philosophy/free-sw.ko.html">&#xd55c;&#xad6d;&#xc5b4;</a> <!-- Korean --></li>  
  <li><a href="/philosophy/free-sw.hu.html">Magyar</a>   <!-- Hungarian --></li>  
  <li><a href="/philosophy/free-sw.nl.html">Nederlands</a>       <!-- Dutch --></li>  
  <li><a href="/philosophy/free-sw.no.html">Norsk</a>    <!-- Norwegian --></li>  
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  <li><a href="/philosophy/free-sw.tl.html">Tagalog</a>  <!-- Tagalog --></li>  
  <li><a href="/philosophy/free-sw.tr.html">T&#x00fc;rk&#x00e7;e</a>     <!-- Turkish --></li>  
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642    
643    <p class="unprintable">Updated:
644    <!-- timestamp start -->
645    $Date$
646    <!-- timestamp end -->
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