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23    <div class="reduced-width">
24    <h2>What is Free Software?</h2>
25    <div class="thin"></div>
26    
27  <h2>What is free software?</h2>  <div class="article">
28    <div class="important">
 <h3>The Free Software Definition</h3>  
   
 <blockquote>  
29  <p>  <p>
30  The free software definition presents the criteria for whether a  &ldquo;Free software&rdquo; means software that respects users'
31  particular software program qualifies as free software.  From time to  freedom and community.  Roughly, it means that <b>the users have the
32  time we revise this definition, to clarify it or to resolve questions  freedom to run, copy, distribute, study, change and improve the
33  about subtle issues.  See the <a href="#History">History section</a>  software</b>.  Thus, &ldquo;free software&rdquo; is a matter of
34  below for a list of changes that affect the definition of free  liberty, not price.  To understand the concept, you should think of
35  software.  &ldquo;free&rdquo; as in &ldquo;free speech,&rdquo; not as in
36    &ldquo;free beer&rdquo;.  We sometimes call it &ldquo;libre
37    software,&rdquo; borrowing the French or Spanish word for
38    &ldquo;free&rdquo; as in freedom, to show we do not mean the software
39    is gratis.
40  </p>  </p>
 </blockquote>  
41    
42  <p>  <p>
43  &ldquo;Free software&rdquo; means software that respects users'  You may have paid money to get copies of a free program, or you may
44  freedom and community.  Roughly, <b>the users have the freedom to run,  have obtained copies at no charge.  But regardless of how you got your
45  copy, distribute, study, change and improve the software</b>.  With these  copies, you always have the freedom to copy and change the software,
46  freedoms, the users (both individually and collectively) control the  even to <a href="/philosophy/selling.html">sell copies</a>.
 program and what it does for them.  
47  </p>  </p>
48    </div>
49    
50  <p>  <p>
51  When users don't control the program, the program controls the users.  We campaign for these freedoms because everyone deserves them.  With
52  The developer controls the program, and through it controls the users.  these freedoms, the users (both individually and collectively) control
53  This nonfree or &ldquo;proprietary&rdquo; program is therefore an  the program and what it does for them.  When users don't control the
54  instrument of unjust power.  program, we call it a &ldquo;nonfree&rdquo; or
55    &ldquo;proprietary&rdquo; program.  The nonfree program controls the
56    users, and the developer controls the program; this makes the
57    program <a href="/philosophy/free-software-even-more-important.html">
58    an instrument of unjust power</a>.
59  </p>  </p>
60    
61  <p>  <p>
62  Thus, &ldquo;free software&rdquo; is a matter of liberty, not price.  &ldquo;Open source&rdquo; is something different: it has a very
63  To understand the concept, you should think of &ldquo;free&rdquo; as  different philosophy based on different values.  Its practical
64  in &ldquo;free speech,&rdquo; not as in &ldquo;free beer&rdquo;.  definition is different too, but nearly all open source programs are
65    in fact free.  We explain the
66    difference in <a href="/philosophy/open-source-misses-the-point.html">
67    Why &ldquo;Open Source&rdquo; misses the point of Free Software</a>.
68    </p>
69    
70    <div class="toc">
71    <hr class="no-display" />
72    <h3 class="no-display">Table of contents</h3>
73    <ul>
74     <li><a href="#fs-definition">The Free Software Definition</a>
75      <ul>
76       <li><a href="#four-freedoms">The four essential freedoms</a></li>
77       <li><a href="#selling">Free software <em>can</em> be commercial</a></li>
78      </ul>
79     </li>
80     <li><a href="#clarifying">Clarifying the Boundary Between Free and Nonfree</a>
81      <ul>
82       <li><a href="#run-the-program">The freedom to run the program as you
83         wish</a></li>
84       <li><a href="#make-changes">The freedom to study the source code and make
85         changes</a></li>
86       <li><a href="#redistribute">The freedom to redistribute if you wish:
87         basic requirements</a></li>
88       <li><a href="#copyleft">Copyleft</a></li>
89       <li><a href="#packaging">Rules about packaging and distribution
90         details</a></li>
91       <li><a href="#exportcontrol">Export regulations</a></li>
92       <li><a href="#legal-details">Legal considerations</a></li>
93       <li><a href="#contracts">Contract-based licenses</a></li>
94      </ul>
95     </li>
96     <li><a href="#in-practice">The Free Software Definition in Practice</a>
97      <ul>
98       <li><a href="#interpretation">How we interpret these criteria</a></li>
99       <li><a href="#get-help">Get help with free licenses</a></li>
100       <li><a href="#terminology">Use the right words when talking about free
101         software</a></li>
102      </ul>
103     </li>
104     <li><a href="#beyond-software">Beyond Software</a></li>
105     <li><a href="#History">History</a></li>
106    </ul>
107    </div>
108    
109    <div class="edu-note" id="fsf-licensing">
110    <p style="font-size:80%">
111    Have a question about free software licensing not answered here?
112    See our other <a href="http://www.fsf.org/licensing">licensing resources</a>,
113    and if necessary contact the FSF Compliance Lab
114    at <a href="mailto:licensing@fsf.org">licensing@fsf.org</a>.</p>
115    <hr class="no-display" />
116    </div>
117    
118    
119    <h3 id="fs-definition" class="subheader">The Free Software Definition</h3>
120    
121    <p>
122    The free software definition presents the criteria for whether a
123    particular software program qualifies as free software.  From time to
124    time we revise this definition, to clarify it or to resolve questions
125    about subtle issues.  See the <a href="#History">History section</a>
126    below for a list of changes that affect the definition of free
127    software.
128  </p>  </p>
129    
130    <h4 id="four-freedoms">The four essential freedoms</h4>
131  <p>  <p>
132  A program is free software if the program's users have the  A program is free software if the program's users have the
133  four essential freedoms:  four essential freedoms: <a href="#f1">[1]</a>
134  </p>  </p>
135    
136  <ul>  <ul class="important">
137    <li>The freedom to run the program, for any purpose (freedom 0).</li>    <li>The freedom to run the program as you wish,
138          for any purpose (freedom 0).</li>
139    <li>The freedom to study how the program works, and change it so it    <li>The freedom to study how the program works, and change it so it
140        does your computing as you wish (freedom 1). Access to the source        does your computing as you wish (freedom 1). Access to the source
141        code is a precondition for this.        code is a precondition for this.
142    </li>    </li>
143    <li>The freedom to redistribute copies so you can help your neighbor    <li>The freedom to redistribute copies so you can help others
144        (freedom 2).        (freedom 2).
145    </li>    </li>
146    <li>The freedom to distribute copies of your modified versions    <li>The freedom to distribute copies of your modified versions
# Line 68  four essential freedoms: Line 151  four essential freedoms:
151  </ul>  </ul>
152    
153  <p>  <p>
154  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
155  you should be free to redistribute copies, either with or without  freedoms.  Otherwise, it is nonfree.  While we can distinguish various
156  modifications, either gratis or charging a fee for distribution, to  nonfree distribution schemes in terms of how far they fall short of
157  <a href="#exportcontrol">anyone anywhere</a>.  Being free to do these  being free, we consider them all equally unethical.</p>
158  things means (among other things) that you do not have to ask or pay  
159  for permission to do so.  <p>In any given scenario, these freedoms must apply to whatever code
160    we plan to make use of, or lead others to make use of.  For instance,
161    consider a program A which automatically launches a program B to
162    handle some cases.  If we plan to distribute A as it stands, that
163    implies users will need B, so we need to judge whether both A and B
164    are free.  However, if we plan to modify A so that it doesn't use B,
165    only A needs to be free; B is not pertinent to that plan.</p>
166    
167    
168    <h4 id="selling">Free software <em>can</em> be commercial</h4>
169    
170    <p>
171    &ldquo;Free software&rdquo; does not mean &ldquo;noncommercial&rdquo;.
172    On the contrary, a free program must be available for commercial use,
173    commercial development, and commercial distribution.  This policy is
174    of fundamental importance&mdash;without this, free software could not
175    achieve its aims.
176  </p>  </p>
177    
178  <p>  <p>
179  You should also have the freedom to make modifications and use them  We want to invite everyone to use the GNU system, including businesses
180  privately in your own work or play, without even mentioning that they  and their workers.  That requires allowing commercial use.  We hope
181  exist.  If you do publish your changes, you should not be required to  that free replacement programs will supplant comparable proprietary
182  notify anyone in particular, or in any particular way.  programs, but they can't do that if businesses are forbidden to use
183    them.  We want commercial products that contain software to include
184    the GNU system, and that would constitute commercial distribution for
185    a price.  Commercial development of free software is no longer
186    unusual; such free commercial software is very important.  Paid,
187    professional support for free software fills an important need.
188    </p>
189    
190    <p>
191    Thus, to exclude commercial use, commercial development or commercial
192    distribution would hobble the free software community and obstruct its
193    path to success.  We must conclude that a program licensed with such
194    restrictions does not qualify as free software.
195    </p>
196    
197    <p>
198    A free program must offer the four freedoms to any would-be user that
199    obtains a copy of the software, who has complied thus far with the
200    conditions of the free license covering the software in any previous
201    distribution of it.  Putting some of the freedoms off limits to some
202    users, or requiring that users pay, in money or in kind, to exercise
203    them, is tantamount to not granting the freedoms in question, and thus
204    renders the program nonfree.
205  </p>  </p>
206    
207    
208    <h3 id="clarifying" class="subheader">Clarifying the Boundary Between Free and Nonfree</h3>
209    
210    <p>In the rest of this article we explain more precisely how far the
211    various freedoms need to extend, on various issues, in order for a
212    program to be free.</p>
213    
214    <h4 id="run-the-program">The freedom to run the program as you wish</h4>
215    
216  <p>  <p>
217  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
218  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
# Line 95  for her purposes, but you are not entitl Line 225  for her purposes, but you are not entitl
225  </p>  </p>
226    
227  <p>  <p>
228  The freedom to redistribute copies must include binary or executable  The freedom to run the program as you wish means that you are not
229  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
230  unmodified versions.  (Distributing programs in runnable form is necessary  functionality the program has, whether it is technically capable of
231  for conveniently installable free operating systems.)  It is OK if there  functioning in any given environment, or whether it is useful for any
232  is no way to produce a binary or executable form for a certain program  particular computing activity.</p>
233  (since some languages don't support that feature), but you must have the  
234  freedom to redistribute such forms should you find or develop a way to  <p>For example, if the code arbitrarily rejects certain meaningful
235  make them.  inputs&mdash;or even fails unconditionally&mdash;that may make the
236  </p>  program less useful, perhaps even totally useless, but it does not
237    deny users the freedom to run the program, so it does not conflict
238    with freedom 0.  If the program is free, the users can overcome the
239    loss of usefulness, because freedoms 1 and 3 permit users and
240    communities to make and distribute modified versions without the
241    arbitrary nuisance code.</p>
242    
243    <p>&ldquo;As you wish&rdquo; includes, optionally, &ldquo;not at
244    all&rdquo; if that is what you wish.  So there is no need for a
245    separate &ldquo;freedom not to run a program.&rdquo;</p>
246    
247    <h4 id="make-changes">The freedom to study the source code and make changes</h4>
248    
249  <p>  <p>
250  In order for freedoms 1 and 3 (the freedom to make changes and the  In order for freedoms 1 and 3 (the freedom to make changes and the
251  freedom to publish the changed versions) to be meaningful, you must have  freedom to publish the changed versions) to be meaningful, you need to have
252  access to the source code of the program.  Therefore, accessibility of  access to the source code of the program.  Therefore, accessibility of
253  source code is a necessary condition for free software.  Obfuscated  source code is a necessary condition for free software.  Obfuscated
254  &ldquo;source code&rdquo; is not real source code and does not count  &ldquo;source code&rdquo; is not real source code and does not count
# Line 120  the original.  If the program is deliver Line 261  the original.  If the program is deliver
261  run someone else's modified versions but refuse to run yours &mdash; a  run someone else's modified versions but refuse to run yours &mdash; a
262  practice known as &ldquo;tivoization&rdquo; or &ldquo;lockdown&rdquo;,  practice known as &ldquo;tivoization&rdquo; or &ldquo;lockdown&rdquo;,
263  or (in its practitioners' perverse terminology) as &ldquo;secure  or (in its practitioners' perverse terminology) as &ldquo;secure
264  boot&rdquo; &mdash; freedom 1 becomes a theoretical fiction rather  boot&rdquo; &mdash; freedom 1 becomes an empty pretense rather than a
265  than a practical freedom.  This is not sufficient.  In other words,  practical reality.  These binaries are not free
266  these binaries are not free software even if the source code they are  software even if the source code they are compiled from is free.
 compiled from is free.  
267  </p>  </p>
268    
269  <p>  <p>
# Line 135  license is too restrictive to qualify as Line 275  license is too restrictive to qualify as
275  </p>  </p>
276    
277  <p>  <p>
278    Whether a change constitutes an improvement is a subjective matter.
279    If your right to modify a program is limited, in substance, to changes that
280    someone else considers an improvement, that program is not free.
281    </p>
282    
283    <p>
284    One special case of freedom 1 is to delete the program's code so it
285    returns after doing nothing, or make it invoke some other program.
286    Thus, freedom 1 includes the &ldquo;freedom to delete the program.&rdquo;
287    </p>
288    
289    <h4 id="redistribute">The freedom to redistribute if you wish: basic
290    requirements</h4>
291    
292    <p>Freedom to distribute (freedoms 2 and 3) means you are free to
293    redistribute copies, either with or without modifications, either
294    gratis or charging a fee for distribution, to
295    <a href="#exportcontrol">anyone anywhere</a>.  Being free to do these
296    things means (among other things) that you do not have to ask or pay
297    for permission to do so.
298    </p>
299    
300    <p>
301    You should also have the freedom to make modifications and use them
302    privately in your own work or play, without even mentioning that they
303    exist.  If you do publish your changes, you should not be required to
304    notify anyone in particular, or in any particular way.
305    </p>
306    
307    <p>
308  Freedom 3 includes the freedom to release your modified versions  Freedom 3 includes the freedom to release your modified versions
309  as free software.  A free license may also permit other ways of  as free software.  A free license may also permit other ways of
310  releasing them; in other words, it does not have to be  releasing them; in other words, it does not have to be
311  a <a href="/copyleft/copyleft.html">copyleft</a> license.  However, a  a <a href="/licenses/copyleft.html">copyleft</a> license.  However, a
312  license that requires modified versions to be nonfree does not qualify  license that requires modified versions to be nonfree does not qualify
313  as a free license.  as a free license.
314  </p>  </p>
315    
316  <p>  <p>
317  In order for these freedoms to be real, they must be permanent and  The freedom to redistribute copies must include binary or executable
318  irrevocable as long as you do nothing wrong; if the developer of the  forms of the program, as well as source code, for both modified and
319  software has the power to revoke the license, or retroactively add  unmodified versions.  (Distributing programs in runnable form is necessary
320  restrictions to its terms, without your doing anything wrong to give  for conveniently installable free operating systems.)  It is OK if there
321  cause, the software is not free.  is no way to produce a binary or executable form for a certain program
322    (since some languages don't support that feature), but you must have the
323    freedom to redistribute such forms should you find or develop a way to
324    make them.
325  </p>  </p>
326    
327    <h4 id="copyleft">Copyleft</h4>
328    
329  <p>  <p>
330  However, certain kinds of rules about the manner of distributing free  Certain kinds of rules about the manner of distributing free
331  software are acceptable, when they don't conflict with the central  software are acceptable, when they don't conflict with the central
332  freedoms.  For example, copyleft (very simply stated) is the rule that  freedoms.  For example, <a href="/licenses/copyleft.html">copyleft</a>
333  when redistributing the program, you cannot add restrictions to deny  (very simply stated) is the rule that when redistributing the program,
334  other people the central freedoms.  This rule does not conflict with  you cannot add restrictions to deny other people the central freedoms.
335  the central freedoms; rather it protects them.  This rule does not conflict with the central freedoms; rather it
336    protects them.
337  </p>  </p>
338    
339  <p>  <p>
340  &ldquo;Free software&rdquo; does not mean &ldquo;noncommercial&rdquo;.  A free  In the GNU project, we use copyleft to protect the four freedoms
341  program must be available for commercial use, commercial development,  legally for everyone.  We believe there are important reasons why
342  and commercial distribution.  Commercial development of free software  <a href="/philosophy/pragmatic.html">it is better to use
343  is no longer unusual; such free commercial software is very important.  copyleft</a>.  However,
344  You may have paid money to get copies of free software, or you may have  <a href="/philosophy/categories.html#Non-CopyleftedFreeSoftware">
345  obtained copies at no charge.  But regardless of how you got your copies,  noncopylefted free software</a> is ethical
346  you always have the freedom to copy and change the software, even to  too.  See <a href="/philosophy/categories.html">Categories of Free
347  <a href="/philosophy/selling.html">sell copies</a>.  Software</a> for a description of how &ldquo;free software,&rdquo;
348    &ldquo;copylefted software&rdquo; and other categories of software
349    relate to each other.
350  </p>  </p>
351    
352  <p>  <h4 id="packaging">Rules about packaging and distribution details</h4>
 Whether a change constitutes an improvement is a subjective matter.  
 If your right to modify a program is limited, in substance, to changes that  
 someone else considers an improvement, that program is not free.  
 </p>  
353    
354  <p>  <p>
355  However, rules about how to package a modified version are acceptable,  Rules about how to package a modified version are acceptable,
356  if they don't substantively limit your freedom to release modified  if they don't substantively limit your freedom to release modified
357  versions, or your freedom to make and use modified versions privately.  versions, or your freedom to make and use modified versions privately.
358  Thus, it is acceptable for the license to require that you change the  Thus, it is acceptable for the license to require that you change the
# Line 190  the program, so you won't have trouble m Line 364  the program, so you won't have trouble m
364  </p>  </p>
365    
366  <p>  <p>
 A special issue arises when a license requires changing the name by  
 which the program will be invoked from other programs.  That  
 effectively hampers you from releasing your changed version so that it  
 can replace the original when invoked by those other programs.  This  
 sort of requirement is acceptable only if there's a suitable aliasing  
 facility that allows you to specify the original program's name as an  
 alias for the modified version.</p>  
   
 <p>  
367  Rules that &ldquo;if you make your version available in this way, you  Rules that &ldquo;if you make your version available in this way, you
368  must make it available in that way also&rdquo; can be acceptable too,  must make it available in that way also&rdquo; can be acceptable too,
369  on the same condition.  An example of such an acceptable rule is one  on the same condition.  An example of such an acceptable rule is one
# Line 211  are also acceptable. Line 376  are also acceptable.
376  </p>  </p>
377    
378  <p>  <p>
379  In the GNU project, we use  A special issue arises when a license requires changing the name by
380  <a href="/copyleft/copyleft.html">copyleft</a>  which the program will be invoked from other programs.  That
381  to protect these freedoms legally for everyone.  But  effectively hampers you from releasing your changed version so that it
382  <a href="/philosophy/categories.html#Non-CopyleftedFreeSoftware">noncopylefted  can replace the original when invoked by those other programs.  This
383  free software</a> also exists.  We believe there are important reasons why  sort of requirement is acceptable only if there's a suitable aliasing
384  <a href="/philosophy/pragmatic.html">it is better to use copyleft</a>,  facility that allows you to specify the original program's name as an
385  but if your program is noncopylefted free software, it is still basically  alias for the modified version.</p>
386  ethical. (See <a href="/philosophy/categories.html">Categories of Free Software</a> for a description of how &ldquo;free software,&rdquo; &ldquo;copylefted software&rdquo; and other categories of software relate to each other.)  
387  </p>  <h4 id="exportcontrol">Export regulations</h4>
388    
389  <p>  <p>
390  Sometimes government <a id="exportcontrol">export control regulations</a>  Sometimes government export control regulations
391  and trade sanctions can constrain your freedom to distribute copies of  and trade sanctions can constrain your freedom to distribute copies of
392  programs internationally.  Software developers do not have the power to  programs internationally.  Software developers do not have the power to
393  eliminate or override these restrictions, but what they can and must do  eliminate or override these restrictions, but what they can and must do
394  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
395  way, the restrictions will not affect activities and people outside the  way, the restrictions will not affect activities and people outside the
396  jurisdictions of these governments.  Thus, free software licenses  jurisdictions of these governments.  Thus, free software licenses
397  must not require obedience to any export regulations as a condition of  must not require obedience to any nontrivial export regulations as a
398  any of the essential freedoms.  condition of exercising any of the essential freedoms.
399  </p>  </p>
400    
401  <p>  <p>
402    Merely mentioning the existence of export regulations, without making
403    them a condition of the license itself, is acceptable since it does
404    not restrict users.  If an export regulation is actually trivial for
405    free software, then requiring it as a condition is not an actual
406    problem; however, it is a potential problem, since a later change in
407    export law could make the requirement nontrivial and thus render the
408    software nonfree.
409    </p>
410    
411    <h4 id="legal-details">Legal considerations</h4>
412    
413    <p>
414    In order for these freedoms to be real, they must be permanent and
415    irrevocable as long as you do nothing wrong; if the developer of the
416    software has the power to revoke the license, or retroactively add
417    restrictions to its terms, without your doing anything wrong to give
418    cause, the software is not free.
419    </p>
420    
421    <p>
422    A free license may not require compliance with the license of a
423    nonfree program.  Thus, for instance, if a license requires you to
424    comply with the licenses of &ldquo;all the programs you use&rdquo;, in
425    the case of a user that runs nonfree programs this would require
426    compliance with the licenses of those nonfree programs; that makes the
427    license nonfree.
428    </p>
429    
430    <p>
431    It is acceptable for a free license to specify which jurisdiction's
432    law applies, or where litigation must be done, or both.
433    </p>
434    
435    <h4 id="contracts">Contract-based licenses</h4>
436    
437    <p>
438  Most free software licenses are based on copyright, and there are limits  Most free software licenses are based on copyright, and there are limits
439  on what kinds of requirements can be imposed through copyright.  If a  on what kinds of requirements can be imposed through copyright.  If a
440  copyright-based license respects freedom in the ways described above, it  copyright-based license respects freedom in the ways described above, it
# Line 252  legitimate, we will have to think about Line 453  legitimate, we will have to think about
453  it is nonfree.  it is nonfree.
454  </p>  </p>
455    
456  <p>  <h3 id="in-practice" class="subheader">The Free Software Definition in Practice</h3>
457  When talking about free software, it is best to avoid using terms  
458  like &ldquo;give away&rdquo; or &ldquo;for free,&rdquo; because those terms imply that  <h4 id="interpretation">How we interpret these criteria</h4>
 the issue is about price, not freedom.  Some common terms such  
 as &ldquo;piracy&rdquo; 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 proper <a href="/philosophy/fs-translations.html">translations of  
 &ldquo;free software&rdquo;</a> into various languages.  
 </p>  
459    
460  <p>  <p>
461  Finally, note that criteria such as those stated in this free software  Note that criteria such as those stated in this free software
462  definition require careful thought for their interpretation.  To decide  definition require careful thought for their interpretation.  To decide
463  whether a specific software license qualifies as a free software license,  whether a specific software license qualifies as a free software license,
464  we judge it based on these criteria to determine whether it fits their  we judge it based on these criteria to determine whether it fits their
# Line 277  a conclusion about a new issue, we often Line 471  a conclusion about a new issue, we often
471  it easier to see why certain licenses do or don't qualify.  it easier to see why certain licenses do or don't qualify.
472  </p>  </p>
473    
474    <h4 id="get-help">Get help with free licenses</h4>
475    
476  <p>  <p>
477  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
478  software license, see our <a href="/licenses/license-list.html">list  software license, see our <a href="/licenses/license-list.html">list
# Line 299  help you can ensure that the license rea Line 495  help you can ensure that the license rea
495  and avoid various practical problems.  and avoid various practical problems.
496  </p>  </p>
497    
498  <h3 id="beyond-software">Beyond Software</h3>  <h4 id="terminology">Use the right words when talking about free software</h4>
499    
500    <p>
501    When talking about free software, it is best to avoid using terms
502    like &ldquo;give away&rdquo; or &ldquo;for free,&rdquo; because those terms imply that
503    the issue is about price, not freedom.  Some common terms such
504    as &ldquo;piracy&rdquo; embody opinions we hope you won't endorse.  See
505    <a href="/philosophy/words-to-avoid.html">Confusing Words and Phrases that
506    are Worth Avoiding</a> for a discussion of these terms.  We also have
507    a list of proper <a href="/philosophy/fs-translations.html">translations of
508    &ldquo;free software&rdquo;</a> into various languages.
509    </p>
510    
511    <p id="open-source">
512    Another group uses the term &ldquo;open source&rdquo; to mean
513    something close (but not identical) to &ldquo;free software&rdquo;.  We
514    prefer the term &ldquo;free software&rdquo; because, once you have heard that
515    it refers to freedom rather than price, it calls to mind freedom.  The
516    word &ldquo;open&rdquo; never refers to freedom.
517    </p>
518    
519    <h3 id="beyond-software" class="subheader">Beyond Software</h3>
520    
521  <p>  <p>
522  <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 311  manuals are in effect part of the softwa Line 528  manuals are in effect part of the softwa
528  The same arguments also make sense for other kinds of works of  The same arguments also make sense for other kinds of works of
529  practical use &mdash; that is to say, works that embody useful knowledge,  practical use &mdash; that is to say, works that embody useful knowledge,
530  such as educational works and reference  such as educational works and reference
531  works.  <a href="http://wikipedia.org">Wikipedia</a> is the best-known  works.  <a href="https://wikipedia.org">Wikipedia</a> is the best-known
532  example.  example.
533  </p>  </p>
534    
# Line 320  Any kind of work <em>can</em> be free, a Line 537  Any kind of work <em>can</em> be free, a
537  has been extended to a definition of <a href="http://freedomdefined.org/">  has been extended to a definition of <a href="http://freedomdefined.org/">
538  free cultural works</a> applicable to any kind of works.  free cultural works</a> applicable to any kind of works.
539  </p>  </p>
540    <hr class="column-limit" />
541  <h3 id="open-source">Open Source?</h3>  </div>
   
 <p>  
 Another group has started using the term &ldquo;open source&rdquo; to mean  
 something close (but not identical) to &ldquo;free software&rdquo;.  We  
 prefer the term &ldquo;free software&rdquo; because, once you have heard that  
 it refers to freedom rather than price, it calls to mind freedom.  The  
 word &ldquo;open&rdquo; <a href="/philosophy/open-source-misses-the-point.html">  
 never refers to freedom</a>.  
 </p>  
542    
543  <h3 id="History">History</h3>  <h3 id="History">History</h3>
544    
545  <p>From time to time we revise this Free Software Definition.  Here is  <p>From time to time we revise this Free Software Definition.  Here is
546  the list of changes, along with links to show exactly what was  the list of substantive changes, along with links to show exactly what
547  changed.</p>  was changed.</p>
548    
549  <ul>  <ul>
550    
551    <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
552    1.169</a>: Explain more clearly why the four freedoms must apply
553    to commercial activity.  Explain why the four freedoms imply the
554    freedom not to run the program and the freedom to delete it, so there
555    is no need to state those as separate requirements.</li>
556    
557    <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
558    1.165</a>: Clarify that arbitrary annoyances in the code do not
559    negate freedom 0, and that freedoms 1 and 3 enable users to remove them.</li>
560    
561    <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
562    1.153</a>: Clarify that freedom to run the program means nothing stops
563    you from making it run.</li>
564    
565    <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
566    1.141</a>: Clarify which code needs to be free.</li>
567    
568    <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
569    1.135</a>: Say each time that freedom 0 is the freedom to run the program
570    as you wish.</li>
571    
572    <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
573    1.134</a>: Freedom 0 is not a matter of the program's functionality.</li>
574    
575    <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
576    1.131</a>: A free license may not require compliance with a nonfree license
577    of another program.</li>
578    
579    <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
580    1.129</a>: State explicitly that choice of law and choice of forum
581    specifications are allowed.  (This was always our policy.)</li>
582    
583    <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
584    1.122</a>: An export control requirement is a real problem if the
585    requirement is nontrivial; otherwise it is only a potential problem.</li>
586    
587    <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
588    1.118</a>: Clarification: the issue is limits on your right to modify,
589    not on what modifications you have made.  And modifications are not limited
590    to &ldquo;improvements&rdquo;</li>
591    
592  <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  <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
593  1.111</a>: Clarify 1.77 by saying that only  1.111</a>: Clarify 1.77 by saying that only
594  retroactive <em>restrictions</em> are unacceptable.  The copyright  retroactive <em>restrictions</em> are unacceptable.  The copyright
# Line 419  licenses.</li> Line 668  licenses.</li>
668    
669  <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
670  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
671  versions you distribute to the author.</li>  versions you distribute to previous developers on request.</li>
672    
673  </ul>  </ul>
674    
675  <p>There are gaps in the version numbers shown above because there are  <p>There are gaps in the version numbers shown above because there are
676  other changes in this page that do not affect the definition as such.  other changes in this page that do not affect the definition or its
677  These changes are in other parts of the page.  You can review the  interpretations.  For instance, the list does not include changes in
678  complete list of changes to the page through  asides, formatting, spelling, punctuation, or other parts of the page.
679    You can review the complete list of changes to the page through
680  the <a href="http://web.cvs.savannah.gnu.org/viewvc/www/philosophy/free-sw.html?root=www&amp;view=log">cvsweb  the <a href="http://web.cvs.savannah.gnu.org/viewvc/www/philosophy/free-sw.html?root=www&amp;view=log">cvsweb
681  interface</a>.</p>  interface</a>.</p>
682    <hr class="column-limit" />
683    
684    <h3 class="footnote">Footnote</h3>
685    <ol>
686    <li id="f1">The reason they are numbered 0, 1, 2 and 3 is historical. Around
687    1990 there were three freedoms, numbered 1, 2 and 3. Then we realized that
688    the freedom to run the program needed to be mentioned explicitly.
689    It was clearly more basic than the other three, so it properly should
690    precede them. Rather than renumber the others, we made it freedom&nbsp;0.</li>
691    </ol>
692  </div>  </div>
693    
694    </div><!-- for id="content", starts in the include above -->
695  <!--#include virtual="/server/footer.html" -->  <!--#include virtual="/server/footer.html" -->
696    <div id="footer" role="contentinfo">
697    <div class="unprintable">
698    
699  <div id="footer">  <p>Please send general FSF &amp; GNU inquiries to
   
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 Please send FSF &amp; GNU inquiries to  
700  <a href="mailto:gnu@gnu.org">&lt;gnu@gnu.org&gt;</a>.  <a href="mailto:gnu@gnu.org">&lt;gnu@gnu.org&gt;</a>.
701  There are also <a href="/contact/">other ways to contact</a>  There are also <a href="/contact/">other ways to contact</a>
702  the FSF.  the FSF.  Broken links and other corrections or suggestions can be sent
703  <br />  to <a href="mailto:webmasters@gnu.org">&lt;webmasters@gnu.org&gt;</a>.</p>
704  Please send broken links and other corrections or suggestions to  
705  <a href="mailto:webmasters@gnu.org">&lt;webmasters@gnu.org&gt;</a>.  <p><!-- TRANSLATORS: Ignore the original text in this paragraph,
706  </p>          replace it with the translation of these two:
707    
708            We work hard and do our best to provide accurate, good quality
709            translations.  However, we are not exempt from imperfection.
710            Please send your comments and general suggestions in this regard
711            to <a href="mailto:web-translators@gnu.org">
712            &lt;web-translators@gnu.org&gt;</a>.</p>
713    
714            <p>For information on coordinating and contributing translations of
715            our web pages, see <a
716            href="/server/standards/README.translations.html">Translations
717            README</a>. -->
718    Please see the <a
719    href="/server/standards/README.translations.html">Translations
720    README</a> for information on coordinating and contributing translations
721    of this article.</p>
722    </div>
723    
724  <p>  <!-- Regarding copyright, in general, standalone pages (as opposed to
725  Please see the       files generated as part of manuals) on the GNU web server should
726  <a href="/server/standards/README.translations.html">Translations       be under CC BY-ND 4.0.  Please do NOT change or remove this
727  README</a> for information on coordinating and submitting       without talking with the webmasters or licensing team first.
728  translations of this article.       Please make sure the copyright date is consistent with the
729  </p>       document.  For web pages, it is ok to list just the latest year the
730         document was modified, or published.
731        
732         If you wish to list earlier years, that is ok too.
733         Either "2001, 2002, 2003" or "2001-2003" are ok for specifying
734         years, as long as each year in the range is in fact a copyrightable
735         year, i.e., a year in which the document was published (including
736         being publicly visible on the web or in a revision control system).
737        
738         There is more detail about copyright years in the GNU Maintainers
739         Information document, www.gnu.org/prep/maintain. -->
740    
741    <p>Copyright &copy; 1996-2002, 2004-2007, 2009-2019, 2021
742    Free Software Foundation, Inc.</p>
743    
 <p>  
 Copyright &copy; 1996-2002, 2004-2007, 2009, 2010, 2012 Free Software  
 Foundation, Inc.  
 </p>  
744  <p>This page is licensed under a <a rel="license"  <p>This page is licensed under a <a rel="license"
745  href="http://creativecommons.org/licenses/by-nd/3.0/us/">Creative  href="http://creativecommons.org/licenses/by-nd/4.0/">Creative
746  Commons Attribution-NoDerivs 3.0 United States License</a>.  Commons Attribution-NoDerivatives 4.0 International License</a>.</p>
 </p>  
747    
748  <p>  <!--#include virtual="/server/bottom-notes.html" -->
749  Updated:  
750    <p class="unprintable">Updated:
751  <!-- timestamp start -->  <!-- timestamp start -->
752  $Date$  $Date$
753  <!-- timestamp end -->  <!-- timestamp end -->
754  </p>  </p>
755  </div>  </div>
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