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7    - GNU Project - Free Software Foundation</title>
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21    <h2>What is Free Software?</h2>
22    <div class="thin"></div>
23    
24    <div class="important">
25    <p>
26    &ldquo;Free software&rdquo; means software that respects users'
27    freedom and community.  Roughly, it means that <b>the users have the
28    freedom to run, copy, distribute, study, change and improve the
29    software</b>.  Thus, &ldquo;free software&rdquo; is a matter of
30    liberty, not price.  To understand the concept, you should think of
31    &ldquo;free&rdquo; as in &ldquo;free speech,&rdquo; not as in
32    &ldquo;free beer.&rdquo;  We sometimes call it &ldquo;libre
33    software,&rdquo; borrowing the French or Spanish word for
34    &ldquo;free&rdquo; as in freedom, to show we do not mean the software
35    is gratis.
36    </p>
37    
38  <h1>The Free Software Definition</h1>  <p>
39    You may have paid money to get copies of a free program, or you may
40    have obtained copies at no charge.  But regardless of how you got your
41    copies, you always have the freedom to copy and change the software,
42    even to <a href="/philosophy/selling.html">sell copies</a>.
43    </p>
44    </div>
45    
46  <p>  <p>
47  We maintain this free software definition to show clearly what must  We campaign for these freedoms because everyone deserves them.  With
48  be true about a particular software program for it to be considered  these freedoms, the users (both individually and collectively) control
49  free software.  the program and what it does for them.  When users don't control the
50    program, we call it a &ldquo;nonfree&rdquo; or
51    &ldquo;proprietary&rdquo; program.  The nonfree program controls the
52    users, and the developer controls the program; this makes the
53    program <a href="/philosophy/free-software-even-more-important.html">
54    an instrument of unjust power</a>.
55  </p>  </p>
56    
57  <p>  <p>
58  <q>Free software</q> is a matter of liberty, not price.  To understand  &ldquo;Open source&rdquo; is something different: it has a very
59  the concept, you should think of <q>free</q> as in <q>free speech,</q>  different philosophy based on different values.  Its practical
60  not as in <q>free beer.</q>  definition is different too, but nearly all open source programs are
61    in fact free.  We explain the
62    difference in <a href="/philosophy/open-source-misses-the-point.html">
63    Why &ldquo;Open Source&rdquo; misses the point of Free Software</a>.
64    </p>
65    
66    <div class="toc">
67    <hr class="no-display" />
68    <h3 class="no-display">Table of contents</h3>
69    <ul>
70     <li><a href="#fs-definition">The Free Software Definition</a>
71      <ul>
72       <li><a href="#four-freedoms">The four essential freedoms</a></li>
73       <li><a href="#selling">Free software <em>can</em> be commercial</a></li>
74      </ul>
75     </li>
76     <li><a href="#clarifying">Clarifying the Boundary Between Free and Nonfree</a>
77      <ul>
78       <li><a href="#run-the-program">The freedom to run the program as you
79         wish</a></li>
80       <li><a href="#make-changes">The freedom to study the source code and make
81         changes</a></li>
82       <li><a href="#redistribute">The freedom to redistribute if you wish:
83         basic requirements</a></li>
84       <li><a href="#copyleft">Copyleft</a></li>
85       <li><a href="#packaging">Rules about packaging and distribution
86         details</a></li>
87       <li><a href="#exportcontrol">Export regulations</a></li>
88       <li><a href="#legal-details">Legal considerations</a></li>
89       <li><a href="#contracts">Contract-based licenses</a></li>
90      </ul>
91     </li>
92     <li><a href="#in-practice">The Free Software Definition in Practice</a>
93      <ul>
94       <li><a href="#interpretation">How we interpret these criteria</a></li>
95       <li><a href="#get-help">Get help with free licenses</a></li>
96       <li><a href="#terminology">Use the right words when talking about free
97         software</a></li>
98      </ul>
99     </li>
100     <li><a href="#beyond-software">Beyond Software</a></li>
101     <li><a href="#History">History</a></li>
102    </ul>
103    </div>
104    
105    <div class="edu-note" id="fsf-licensing" role="complementary">
106    <p style="font-size:80%">
107    Have a question about free software licensing not answered here?
108    See our other <a href="http://www.fsf.org/licensing">licensing resources</a>,
109    and if necessary contact the FSF Compliance Lab
110    at <a href="mailto:licensing@fsf.org">licensing@fsf.org</a>.</p>
111    <hr class="no-display" />
112    </div>
113    
114    
115    <h3 id="fs-definition">The Free Software Definition</h3>
116    
117    <p>
118    The free software definition presents the criteria for whether a
119    particular software program qualifies as free software.  From time to
120    time we revise this definition, to clarify it or to resolve questions
121    about subtle issues.  See the <a href="#History">History section</a>
122    below for a list of changes that affect the definition of free
123    software.
124  </p>  </p>
125    
126    <h4 id="four-freedoms">The four essential freedoms</h4>
127  <p>  <p>
128  Free software is a matter of the users' freedom to run, copy, distribute,  A program is free software if the program's users have the
129  study, change and improve the software.  More precisely, it refers to  four essential freedoms: <a href="#f1">[1]</a>
 four kinds of freedom, for the users of the software:  
130  </p>  </p>
131    
132  <ul>  <ul class="important">
133    <li>The freedom to run the program, for any purpose (freedom 0).</li>    <li>The freedom to run the program as you wish,
134    <li>The freedom to study how the program works, and adapt it to        for any purpose (freedom 0).</li>
135        your needs (freedom 1). Access to the source code is a precondition    <li>The freedom to study how the program works, and change it so it
136        for this.        does your computing as you wish (freedom 1). Access to the source
137          code is a precondition for this.
138    </li>    </li>
139    <li>The freedom to redistribute copies so you can help your neighbor    <li>The freedom to redistribute copies so you can help others
140        (freedom 2).        (freedom 2).
141    </li>    </li>
142    <li>The freedom to improve the program, and release your improvements    <li>The freedom to distribute copies of your modified versions
143        to the public, so that the whole community benefits (freedom 3).        to others (freedom 3).  By doing this you can give the whole
144          community a chance to benefit from your changes.
145        Access to the source code is a precondition for this.        Access to the source code is a precondition for this.
146    </li>    </li>
147  </ul>  </ul>
148    
149  <p>  <p>
150  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
151  you should be free to redistribute copies, either with or without  freedoms.  Otherwise, it is nonfree.  While we can distinguish various
152  modifications, either gratis or charging a fee for distribution, to  nonfree distribution schemes in terms of how far they fall short of
153  <a href="#exportcontrol">anyone anywhere</a>.  Being free to do these  being free, we consider them all equally unethical.</p>
154  things means (among other things) that you do not have to ask or pay  
155  for permission.  <p>In any given scenario, these freedoms must apply to whatever code
156    we plan to make use of, or lead others to make use of.  For instance,
157    consider a program A which automatically launches a program B to
158    handle some cases.  If we plan to distribute A as it stands, that
159    implies users will need B, so we need to judge whether both A and B
160    are free.  However, if we plan to modify A so that it doesn't use B,
161    only A needs to be free; B is not pertinent to that plan.</p>
162    
163    
164    <h4 id="selling">Free software <em>can</em> be commercial</h4>
165    
166    <p>
167    &ldquo;Free software&rdquo; does not mean &ldquo;noncommercial.&rdquo;
168    On the contrary, a free program must be available for commercial use,
169    commercial development, and commercial distribution.  This policy is
170    of fundamental importance&mdash;without this, free software could not
171    achieve its aims.
172  </p>  </p>
173    
174  <p>  <p>
175  You should also have the freedom to make modifications and use them  We want to invite everyone to use the GNU system, including businesses
176  privately in your own work or play, without even mentioning that they  and their workers.  That requires allowing commercial use.  We hope
177  exist.  If you do publish your changes, you should not be required to  that free replacement programs will supplant comparable proprietary
178  notify anyone in particular, or in any particular way.  programs, but they can't do that if businesses are forbidden to use
179    them.  We want commercial products that contain software to include
180    the GNU system, and that would constitute commercial distribution for
181    a price.  Commercial development of free software is no longer
182    unusual; such free commercial software is very important.  Paid,
183    professional support for free software fills an important need.
184    </p>
185    
186    <p>
187    Thus, to exclude commercial use, commercial development or commercial
188    distribution would hobble the free software community and obstruct its
189    path to success.  We must conclude that a program licensed with such
190    restrictions does not qualify as free software.
191    </p>
192    
193    <p>
194    A free program must offer the four freedoms to any would-be user that
195    obtains a copy of the software, who has complied thus far with the
196    conditions of the free license covering the software in any previous
197    distribution of it.  Putting some of the freedoms off limits to some
198    users, or requiring that users pay, in money or in kind, to exercise
199    them, is tantamount to not granting the freedoms in question, and thus
200    renders the program nonfree.
201  </p>  </p>
202    
203    
204    <h3 id="clarifying">Clarifying the Boundary Between Free and Nonfree</h3>
205    
206    <p>In the rest of this article we explain more precisely how far the
207    various freedoms need to extend, on various issues, in order for a
208    program to be free.</p>
209    
210    <h4 id="run-the-program">The freedom to run the program as you wish</h4>
211    
212  <p>  <p>
213  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
214  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
215  overall job and purpose, without being required to communicate about it  overall job and purpose, without being required to communicate about it
216  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
217  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>
218  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,
219  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
220  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.
221  </p>  </p>
222    
223  <p>  <p>
224    The freedom to run the program as you wish means that you are not
225    forbidden or stopped from making it run.  This has nothing to do with what
226    functionality the program has, whether it is technically capable of
227    functioning in any given environment, or whether it is useful for any
228    particular computing activity.</p>
229    
230    <p>For example, if the code arbitrarily rejects certain meaningful
231    inputs&mdash;or even fails unconditionally&mdash;that may make the
232    program less useful, perhaps even totally useless, but it does not
233    deny users the freedom to run the program, so it does not conflict
234    with freedom 0.  If the program is free, the users can overcome the
235    loss of usefulness, because freedoms 1 and 3 permit users and
236    communities to make and distribute modified versions without the
237    arbitrary nuisance code.</p>
238    
239    <p>&ldquo;As you wish&rdquo; includes, optionally, &ldquo;not at
240    all&rdquo; if that is what you wish.  So there is no need for a
241    separate &ldquo;freedom not to run a program.&rdquo;</p>
242    
243    <h4 id="make-changes">The freedom to study the source code and make changes</h4>
244    
245    <p>
246    In order for freedoms 1 and 3 (the freedom to make changes and the
247    freedom to publish the changed versions) to be meaningful, you need to have
248    access to the source code of the program.  Therefore, accessibility of
249    source code is a necessary condition for free software.  Obfuscated
250    &ldquo;source code&rdquo; is not real source code and does not count
251    as source code.
252    </p>
253    
254    <p>
255    Freedom 1 includes the freedom to use your changed version in place of
256    the original.  If the program is delivered in a product designed to
257    run someone else's modified versions but refuse to run yours&mdash;a
258    practice known as &ldquo;tivoization&rdquo; or &ldquo;lockdown,&rdquo;
259    or (in its practitioners' perverse terminology) as &ldquo;secure
260    boot&rdquo;&mdash;freedom 1 becomes an empty pretense rather than a
261    practical reality.  These binaries are not free
262    software even if the source code they are compiled from is free.
263    </p>
264    
265    <p>
266    One important way to modify a program is by merging in available free
267    subroutines and modules.  If the program's license says that you
268    cannot merge in a suitably licensed existing module&mdash;for instance, if it
269    requires you to be the copyright holder of any code you add&mdash;then the
270    license is too restrictive to qualify as free.
271    </p>
272    
273    <p>
274    Whether a change constitutes an improvement is a subjective matter.
275    If your right to modify a program is limited, in substance, to changes that
276    someone else considers an improvement, that program is not free.
277    </p>
278    
279    <p>
280    One special case of freedom 1 is to delete the program's code so it
281    returns after doing nothing, or make it invoke some other program.
282    Thus, freedom 1 includes the &ldquo;freedom to delete the program.&rdquo;
283    </p>
284    
285    <h4 id="redistribute">The freedom to redistribute if you wish: basic
286    requirements</h4>
287    
288    <p>Freedom to distribute (freedoms 2 and 3) means you are free to
289    redistribute copies, either with or without modifications, either
290    gratis or charging a fee for distribution, to
291    <a href="#exportcontrol">anyone anywhere</a>.  Being free to do these
292    things means (among other things) that you do not have to ask or pay
293    for permission to do so.
294    </p>
295    
296    <p>
297    You should also have the freedom to make modifications and use them
298    privately in your own work or play, without even mentioning that they
299    exist.  If you do publish your changes, you should not be required to
300    notify anyone in particular, or in any particular way.
301    </p>
302    
303    <p>
304    Freedom 3 includes the freedom to release your modified versions
305    as free software.  A free license may also permit other ways of
306    releasing them; in other words, it does not have to be
307    a <a href="/licenses/copyleft.html">copyleft</a> license.  However, a
308    license that requires modified versions to be nonfree does not qualify
309    as a free license.
310    </p>
311    
312    <p>
313  The freedom to redistribute copies must include binary or executable  The freedom to redistribute copies must include binary or executable
314  forms of the program, as well as source code, for both modified and  forms of the program, as well as source code, for both modified and
315  unmodified versions.  (Distributing programs in runnable form is necessary  unmodified versions.  (Distributing programs in runnable form is necessary
316  for conveniently installable free operating systems.)  It is ok if there  for conveniently installable free operating systems.)  It is OK if there
317  is no way to produce a binary or executable form for a certain program  is no way to produce a binary or executable form for a certain program
318  (since some languages don't support that feature), but you must have the  (since some languages don't support that feature), but you must have the
319  freedom to redistribute such forms should you find or develop a way to  freedom to redistribute such forms should you find or develop a way to
320  make them.  make them.
321  </p>  </p>
322    
323    <h4 id="copyleft">Copyleft</h4>
324    
325  <p>  <p>
326  In order for the freedoms to make changes, and to publish improved  Certain kinds of rules about the manner of distributing free
327  versions, to be meaningful, you must have access to the source code of  software are acceptable, when they don't conflict with the central
328  the program.  Therefore, accessibility of source code is a necessary  freedoms.  For example, <a href="/licenses/copyleft.html">copyleft</a>
329  condition for free software.  (very simply stated) is the rule that when redistributing the program,
330    you cannot add restrictions to deny other people the central freedoms.
331    This rule does not conflict with the central freedoms; rather it
332    protects them.
333  </p>  </p>
334    
335  <p>  <p>
336  One important way to modify a program is by merging in available  In the GNU project, we use copyleft to protect the four freedoms
337  free subroutines and modules.  If the program's license says that you  legally for everyone.  We believe there are important reasons why
338  cannot merge in an existing module, such as if it requires you to be the  <a href="/philosophy/pragmatic.html">it is better to use
339  copyright holder of any code you add, then the license is too restrictive  copyleft</a>.  However,
340  to qualify as free.  <a href="/philosophy/categories.html#Non-CopyleftedFreeSoftware">
341    noncopylefted free software</a> is ethical
342    too.  See <a href="/philosophy/categories.html">Categories of Free
343    Software</a> for a description of how &ldquo;free software,&rdquo;
344    &ldquo;copylefted software&rdquo; and other categories of software
345    relate to each other.
346  </p>  </p>
347    
348    <h4 id="packaging">Rules about packaging and distribution details</h4>
349    
350  <p>  <p>
351  In order for these freedoms to be real, they must be irrevocable as  Rules about how to package a modified version are acceptable,
352  long as you do nothing wrong; if the developer of the software has the  if they don't substantively limit your freedom to release modified
353  power to revoke the license, without your doing anything to give cause,  versions, or your freedom to make and use modified versions privately.
354  the software is not free.  Thus, it is acceptable for the license to require that you change the
355    name of the modified version, remove a logo, or identify your
356    modifications as yours.  As long as these requirements are not so
357    burdensome that they effectively hamper you from releasing your
358    changes, they are acceptable; you're already making other changes to
359    the program, so you won't have trouble making a few more.
360  </p>  </p>
361    
362  <p>  <p>
363  However, certain kinds of rules about the manner of distributing free  Rules that &ldquo;if you make your version available in this way, you
364  software are acceptable, when they don't conflict with the central  must make it available in that way also&rdquo; can be acceptable too,
365  freedoms.  For example, copyleft (very simply stated) is the rule that  on the same condition.  An example of such an acceptable rule is one
366  when redistributing the program, you cannot add restrictions to deny  saying that if you have distributed a
367  other people the central freedoms.  This rule does not conflict with  modified version and a previous developer asks for a copy of it, you
368  the central freedoms; rather it protects them.  must send one.  (Note that such a rule still leaves you the choice of
369    whether to distribute your version at all.)  Rules that require release
370    of source code to the users for versions that you put into public use
371    are also acceptable.
372  </p>  </p>
373    
374  <p>  <p>
375  You may have paid money to get copies of free software, or you may have  A special issue arises when a license requires changing the name by
376  obtained copies at no charge.  But regardless of how you got your copies,  which the program will be invoked from other programs.  That
377  you always have the freedom to copy and change the software, even to  effectively hampers you from releasing your changed version so that it
378  <a href="/philosophy/selling.html">sell copies</a>.  can replace the original when invoked by those other programs.  This
379  </p>  sort of requirement is acceptable only if there's a suitable aliasing
380    facility that allows you to specify the original program's name as an
381    alias for the modified version.</p>
382    
383    <h4 id="exportcontrol">Export regulations</h4>
384    
385  <p>  <p>
386  <q>Free software</q> does not mean <q>non-commercial.</q>  A free  Sometimes government export control regulations
387  program must be available for commercial use, commercial development,  and trade sanctions can constrain your freedom to distribute copies of
388  and commercial distribution.  Commercial development of free software  programs internationally.  Software developers do not have the power to
389  is no longer unusual; such free commercial software is very important.  eliminate or override these restrictions, but what they can and must do
390    is refuse to impose them as conditions of use of the program.  In this
391    way, the restrictions will not affect activities and people outside the
392    jurisdictions of these governments.  Thus, free software licenses
393    must not require obedience to any nontrivial export regulations as a
394    condition of exercising any of the essential freedoms.
395  </p>  </p>
396    
397  <p>  <p>
398  Rules about how to package a modified version are acceptable, if they  Merely mentioning the existence of export regulations, without making
399  don't substantively block your freedom to release modified versions, or  them a condition of the license itself, is acceptable since it does
400  your freedom to make and use modified versions privately.  Rules that <q>if  not restrict users.  If an export regulation is actually trivial for
401  you make your version available in this way, you must make it available in  free software, then requiring it as a condition is not an actual
402  that way also</q> can be acceptable too, on the same condition.  (Note that  problem; however, it is a potential problem, since a later change in
403  such a rule still leaves you the choice of whether to publish your version  export law could make the requirement nontrivial and thus render the
404  at all.)  Rules that require release of source code to the users for  software nonfree.
 versions that you put into public use are also acceptable.  It is also  
 acceptable for the license to require that, if you have distributed a  
 modified version and a previous developer asks for a copy of it, you  
 must send one, or that you identify yourself on your modifications.  
405  </p>  </p>
406    
407    <h4 id="legal-details">Legal considerations</h4>
408    
409  <p>  <p>
410  In the GNU project, we use  In order for these freedoms to be real, they must be permanent and
411  <q><a href="/copyleft/copyleft.html">copyleft</a></q>  irrevocable as long as you do nothing wrong; if the developer of the
412  to protect these freedoms legally for everyone.  But  software has the power to revoke the license, or retroactively add
413  <a href="/philosophy/categories.html#Non-CopyleftedFreeSoftware">non-copylefted  restrictions to its terms, without your doing anything wrong to give
414  free software</a> also exists.  We believe there are important reasons why  cause, the software is not free.
 <a href="/philosophy/pragmatic.html"> it is better to use copyleft</a>,  
 but if your program is non-copylefted free software, we can still  
 use it.  
415  </p>  </p>
416    
417  <p>  <p>
418  See <a href="/philosophy/categories.html">Categories of Free Software</a>  A free license may not require compliance with the license of a
419  for a description of how <q>free software,</q> <q>copylefted software</q>  nonfree program.  Thus, for instance, if a license requires you to
420  and other categories of software relate to each other.  comply with the licenses of &ldquo;all the programs you use,&rdquo; in
421    the case of a user that runs nonfree programs this would require
422    compliance with the licenses of those nonfree programs; that makes the
423    license nonfree.
424  </p>  </p>
425    
426  <p>  <p>
427  Sometimes government <a id="exportcontrol">export control regulations</a>  It is acceptable for a free license to specify which jurisdiction's
428  and trade sanctions can constrain your freedom to distribute copies of  law applies, or where litigation must be done, or both.
 programs internationally.  Software developers do not have the power to  
 eliminate or override these restrictions, but what they can and must do  
 is refuse to impose them as conditions of use of the program.  In this  
 way, the restrictions will not affect activities and people outside the  
 jurisdictions of these governments.  
429  </p>  </p>
430    
431    <h4 id="contracts">Contract-based licenses</h4>
432    
433  <p>  <p>
434  Most free software licenses are based on copyright, and there are limits  Most free software licenses are based on copyright, and there are limits
435  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 176  is unlikely to have some other sort of p Line 438  is unlikely to have some other sort of p
438  (though this does happen occasionally).  However, some free software  (though this does happen occasionally).  However, some free software
439  licenses are based on contracts, and contracts can impose a much larger  licenses are based on contracts, and contracts can impose a much larger
440  range of possible restrictions.  That means there are many possible ways  range of possible restrictions.  That means there are many possible ways
441  such a license could be unacceptably restrictive and non-free.  such a license could be unacceptably restrictive and nonfree.
442  </p>  </p>
443    
444  <p>  <p>
# Line 184  We can't possibly list all the ways that Line 446  We can't possibly list all the ways that
446  contract-based license restricts the user in an unusual way that  contract-based license restricts the user in an unusual way that
447  copyright-based licenses cannot, and which isn't mentioned here as  copyright-based licenses cannot, and which isn't mentioned here as
448  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
449  it is non-free.  it is nonfree.
450  </p>  </p>
451    
452  <p>  <h3 id="in-practice">The Free Software Definition in Practice</h3>
453  When talking about free software, it is best to avoid using terms  
454  like <q>give away</q> or <q>for free,</q> 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 <q>piracy</q> embody opinions we hope you won't endorse.  See  
 <a href="/philosophy/words-to-avoid.html">Confusing Words and Phrases that  
 are Worth Avoiding</a> for a discussion of these terms.  We also have  
 a list of <a href="/philosophy/fs-translations.html">translations of  
 <q>free software</q></a> into various languages.  
 </p>  
455    
456  <p>  <p>
457  Finally, note that criteria such as those stated in this free software  Note that criteria such as those stated in this free software
458  definition require careful thought for their interpretation.  To decide  definition require careful thought for their interpretation.  To decide
459  whether a specific software license qualifies as a free software license,  whether a specific software license qualifies as a free software license,
460  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 212  a conclusion about a new issue, we often Line 467  a conclusion about a new issue, we often
467  it easier to see why certain licenses do or don't qualify.  it easier to see why certain licenses do or don't qualify.
468  </p>  </p>
469    
470    <h4 id="get-help">Get help with free licenses</h4>
471    
472  <p>  <p>
473  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
474  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 478  listed there, you can ask us about it by
478  </p>  </p>
479    
480  <p>  <p>
481  If you are contemplating writing a new license, please contact the FSF  If you are contemplating writing a new license, please contact the
482  by writing to that address. The proliferation of different free software  Free Software Foundation first by writing to that address. The
483  licenses means increased work for users in understanding the licenses;  proliferation of different free software licenses means increased work
484  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
485  meets your needs.  find an existing free software license that meets your needs.
486  </p>  </p>
487    
488  <p>  <p>
489  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
490  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
491  and avoid various practical problems.  and avoid various practical problems.
492  </p>  </p>
493    
494  <h2>Open Source?</h2>  <h4 id="terminology">Use the right words when talking about free software</h4>
495    
496  <p>  <p>
497  Another group has started using the term <q>open source</q> to mean  When talking about free software, it is best to avoid using terms
498  something close (but not identical) to <q>free software.</q>  We prefer  like &ldquo;give away&rdquo; or &ldquo;for free,&rdquo; because those terms imply that
499  the term <q>free software</q> because, once you have heard it refers to  the issue is about price, not freedom.  Some common terms such
500  freedom rather than price, <a href="free-software-for-freedom.html">it  as &ldquo;piracy&rdquo; embody opinions we hope you won't endorse.  See
501  calls to mind freedom</a>.  The word <q>open</q> never does that.  <a href="/philosophy/words-to-avoid.html">Confusing Words and Phrases that
502    are Worth Avoiding</a> for a discussion of these terms.  We also have
503    a list of proper <a href="/philosophy/fs-translations.html">translations of
504    &ldquo;free software&rdquo;</a> into various languages.
505  </p>  </p>
506    
507  <p><a href="/philosophy/philosophy.html">Other Texts to Read</a></p>  <p id="open-source">
508    Another group uses the term &ldquo;open source&rdquo; to mean
509  </div>  something close (but not identical) to &ldquo;free software.&rdquo;  We
510    prefer the term &ldquo;free software&rdquo; because, once you have heard that
511    it refers to freedom rather than price, it calls to mind freedom.  The
512  <!--#include virtual="/server/footer.html" -->  word &ldquo;open&rdquo; never refers to freedom.
513    </p>
514    
515  <div id="footer">  <h3 id="beyond-software">Beyond Software</h3>
516    
517  <p>  <p>
518  Please send FSF &amp; GNU inquiries to  <a href="/philosophy/free-doc.html">Software manuals must be free</a>,
519  <a href="mailto:gnu@gnu.org"><em>gnu@gnu.org</em></a>.  for the same reasons that software must be free, and because the
520  There are also <a href="http://www.fsf.org/about/contact.html">other ways to contact</a>  manuals are in effect part of the software.
 the FSF.  
 <br />  
 Please send broken links and other corrections (or suggestions) to  
 <a href="mailto:webmasters@gnu.org"><em>webmasters@gnu.org</em></a>.  
521  </p>  </p>
522    
523  <p>  <p>
524  Please see the  The same arguments also make sense for other kinds of works of
525  <a href="/server/standards/README.translations.html">Translations  practical use&mdash;that is to say, works that embody useful knowledge,
526  README</a> for information on coordinating and submitting  such as educational works and reference
527  translations of this article.  works.  <a href="https://wikipedia.org">Wikipedia</a> is the best-known
528    example.
529  </p>  </p>
530    
531  <p>  <p>
532  Copyright (C) 1996, 1997, 1998, 1999, 2000, 2001, 2002, 2003, 2004,  Any kind of work <em>can</em> be free, and the definition of free software
533  2005, 2006 <br /> Free Software Foundation, Inc., 51 Franklin St,  has been extended to a definition of <a href="http://freedomdefined.org/">
534  Fifth Floor, Boston, MA 02110-1301,  USA  free cultural works</a> applicable to any kind of works.
 <br />  
 Verbatim copying and distribution of this entire article is  
 permitted in any medium without royalty provided this notice is  
 preserved.  
535  </p>  </p>
536    
537  <p>  <h3 id="History">History</h3>
 Updated:  
 <!-- timestamp start -->  
 $Date$ $Author$  
 <!-- timestamp end -->  
 </p>  
 </div>  
538    
539  <div id="translations">  <p>From time to time we revise this Free Software Definition.  Here is
540  <h4>Translations of this page</h4>  the list of substantive changes, along with links to show exactly what
541    was changed.</p>
542    
543    <ul>
544    
545    <li><a href="//web.cvs.savannah.gnu.org/viewvc/www/philosophy/free-sw.html?root=www&amp;r1=1.168&amp;r2=1.169">Version
546    1.169</a>: Explain more clearly why the four freedoms must apply
547    to commercial activity.  Explain why the four freedoms imply the
548    freedom not to run the program and the freedom to delete it, so there
549    is no need to state those as separate requirements.</li>
550    
551    <li><a href="//web.cvs.savannah.gnu.org/viewvc/www/philosophy/free-sw.html?root=www&amp;r1=1.164&amp;r2=1.165">Version
552    1.165</a>: Clarify that arbitrary annoyances in the code do not
553    negate freedom 0, and that freedoms 1 and 3 enable users to remove them.</li>
554    
555    <li><a href="//web.cvs.savannah.gnu.org/viewvc/www/philosophy/free-sw.html?root=www&amp;r1=1.152&amp;r2=1.153">Version
556    1.153</a>: Clarify that freedom to run the program means nothing stops
557    you from making it run.</li>
558    
559    <li><a href="//web.cvs.savannah.gnu.org/viewvc/www/philosophy/free-sw.html?root=www&amp;r1=1.140&amp;r2=1.141">Version
560    1.141</a>: Clarify which code needs to be free.</li>
561    
562    <li><a href="//web.cvs.savannah.gnu.org/viewvc/www/philosophy/free-sw.html?root=www&amp;r1=1.134&amp;r2=1.135">Version
563    1.135</a>: Say each time that freedom 0 is the freedom to run the program
564    as you wish.</li>
565    
566    <li><a href="//web.cvs.savannah.gnu.org/viewvc/www/philosophy/free-sw.html?root=www&amp;r1=1.133&amp;r2=1.134">Version
567    1.134</a>: Freedom 0 is not a matter of the program's functionality.</li>
568    
569    <li><a href="//web.cvs.savannah.gnu.org/viewvc/www/philosophy/free-sw.html?root=www&amp;r1=1.130&amp;r2=1.131">Version
570    1.131</a>: A free license may not require compliance with a nonfree license
571    of another program.</li>
572    
573    <li><a href="//web.cvs.savannah.gnu.org/viewvc/www/philosophy/free-sw.html?root=www&amp;r1=1.128&amp;r2=1.129">Version
574    1.129</a>: State explicitly that choice of law and choice of forum
575    specifications are allowed.  (This was always our policy.)</li>
576    
577    <li><a href="//web.cvs.savannah.gnu.org/viewvc/www/philosophy/free-sw.html?root=www&amp;r1=1.121&amp;r2=1.122">Version
578    1.122</a>: An export control requirement is a real problem if the
579    requirement is nontrivial; otherwise it is only a potential problem.</li>
580    
581    <li><a href="//web.cvs.savannah.gnu.org/viewvc/www/philosophy/free-sw.html?root=www&amp;r1=1.117&amp;r2=1.118">Version
582    1.118</a>: Clarification: the issue is limits on your right to modify,
583    not on what modifications you have made.  And modifications are not limited
584    to &ldquo;improvements&rdquo;</li>
585    
586    <li><a href="//web.cvs.savannah.gnu.org/viewvc/www/philosophy/free-sw.html?root=www&amp;r1=1.110&amp;r2=1.111">Version
587    1.111</a>: Clarify 1.77 by saying that only
588    retroactive <em>restrictions</em> are unacceptable.  The copyright
589    holders can always grant additional <em>permission</em> for use of the
590    work by releasing the work in another way in parallel.</li>
591    
592    <li><a href="//web.cvs.savannah.gnu.org/viewvc/www/philosophy/free-sw.html?root=www&amp;r1=1.104&amp;r2=1.105">Version
593    1.105</a>: Reflect, in the brief statement of freedom 1, the point
594    (already stated in version 1.80) that it includes really using your modified
595    version for your computing.</li>
596    
597    <li><a href="//web.cvs.savannah.gnu.org/viewvc/www/philosophy/free-sw.html?root=www&amp;r1=1.91&amp;r2=1.92">Version
598    1.92</a>: Clarify that obfuscated code does not qualify as source code.</li>
599    
600    <li><a href="//web.cvs.savannah.gnu.org/viewvc/www/philosophy/free-sw.html?root=www&amp;r1=1.89&amp;r2=1.90">Version
601    1.90</a>: Clarify that freedom 3 means the right to distribute copies
602    of your own modified or improved version, not a right to participate
603    in someone else's development project.</li>
604    
605    <li><a href="//web.cvs.savannah.gnu.org/viewvc/www/philosophy/free-sw.html?root=www&amp;r1=1.88&amp;r2=1.89">Version
606    1.89</a>: Freedom 3 includes the right to release modified versions as
607    free software.</li>
608    
609    <li><a href="//web.cvs.savannah.gnu.org/viewvc/www/philosophy/free-sw.html?root=www&amp;r1=1.79&amp;r2=1.80">Version
610    1.80</a>: Freedom 1 must be practical, not just theoretical;
611    i.e., no tivoization.</li>
612    
613    <li><a href="//web.cvs.savannah.gnu.org/viewvc/www/philosophy/free-sw.html?root=www&amp;r1=1.76&amp;r2=1.77">Version
614    1.77</a>: Clarify that all retroactive changes to the license are
615    unacceptable, even if it's not described as a complete
616    replacement.</li>
617    
618    <li><a href="//web.cvs.savannah.gnu.org/viewvc/www/philosophy/free-sw.html?root=www&amp;r1=1.73&amp;r2=1.74">Version
619    1.74</a>: Four clarifications of points not explicit enough, or stated
620    in some places but not reflected everywhere:
621    <ul>
622    <li>&ldquo;Improvements&rdquo; does not mean the license can
623    substantively limit what kinds of modified versions you can release.
624    Freedom 3 includes distributing modified versions, not just changes.</li>
625    <li>The right to merge in existing modules
626    refers to those that are suitably licensed.</li>
627    <li>Explicitly state the conclusion of the point about export controls.</li>
628    <li>Imposing a license change constitutes revoking the old license.</li>
629    </ul>
630    </li>
631    
632    <li><a href="//web.cvs.savannah.gnu.org/viewvc/www/philosophy/free-sw.html?root=www&amp;r1=1.56&amp;r2=1.57">Version
633    1.57</a>: Add &quot;Beyond Software&quot; section.</li>
634    
635    <li><a href="//web.cvs.savannah.gnu.org/viewvc/www/philosophy/free-sw.html?root=www&amp;r1=1.45&amp;r2=1.46">Version
636    1.46</a>: Clarify whose purpose is significant in the freedom to run
637    the program for any purpose.</li>
638    
639    <li><a href="//web.cvs.savannah.gnu.org/viewvc/www/philosophy/free-sw.html?root=www&amp;r1=1.40&amp;r2=1.41">Version
640    1.41</a>: Clarify wording about contract-based licenses.</li>
641    
642    <li><a href="//web.cvs.savannah.gnu.org/viewvc/www/philosophy/free-sw.html?root=www&amp;r1=1.39&amp;r2=1.40">Version
643    1.40</a>: Explain that a free license must allow to you use other
644    available free software to create your modifications.</li>
645    
646    <li><a href="//web.cvs.savannah.gnu.org/viewvc/www/philosophy/free-sw.html?root=www&amp;r1=1.38&amp;r2=1.39">Version
647    1.39</a>: Note that it is acceptable for a license to require you to
648    provide source for versions of the software you put into public
649    use.</li>
650    
651    <li><a href="//web.cvs.savannah.gnu.org/viewvc/www/philosophy/free-sw.html?root=www&amp;r1=1.30&amp;r2=1.31">Version
652    1.31</a>: Note that it is acceptable for a license to require you to
653    identify yourself as the author of modifications.  Other minor
654    clarifications throughout the text.</li>
655    
656    <li><a href="//web.cvs.savannah.gnu.org/viewvc/www/philosophy/free-sw.html?root=www&amp;r1=1.22&amp;r2=1.23">Version
657    1.23</a>: Address potential problems related to contract-based
658    licenses.</li>
659    
660    <li><a href="//web.cvs.savannah.gnu.org/viewvc/www/philosophy/free-sw.html?root=www&amp;r1=1.15&amp;r2=1.16">Version
661    1.16</a>: Explain why distribution of binaries is important.</li>
662    
663    <li><a href="//web.cvs.savannah.gnu.org/viewvc/www/philosophy/free-sw.html?root=www&amp;r1=1.10&amp;r2=1.11">Version
664    1.11</a>: Note that a free license may require you to send a copy of
665    versions you distribute to previous developers on request.</li>
666    
 <!-- Please keep this list alphabetical, and in the original -->  
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  <li><a href="/philosophy/free-sw.sl.html">Slovinsko</a>        <!--- Slovenian --></li>  
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667  </ul>  </ul>
668    
669    <p>There are gaps in the version numbers shown above because there are
670    other changes in this page that do not affect the definition or its
671    interpretations.  For instance, the list does not include changes in
672    asides, formatting, spelling, punctuation, or other parts of the page.
673    You can review the complete list of changes to the page through
674    the <a href="//web.cvs.savannah.gnu.org/viewvc/www/philosophy/free-sw.html?root=www&amp;view=log">cvsweb
675    interface</a>.</p>
676    <div class="column-limit"></div>
677    
678    <h3 class="footnote">Footnote</h3>
679    <ol>
680    <li id="f1">The reason they are numbered 0, 1, 2 and 3 is historical. Around
681    1990 there were three freedoms, numbered 1, 2 and 3. Then we realized that
682    the freedom to run the program needed to be mentioned explicitly.
683    It was clearly more basic than the other three, so it properly should
684    precede them. Rather than renumber the others, we made it freedom&nbsp;0.</li>
685    </ol>
686  </div>  </div>
687    
688    </div><!-- for id="content", starts in the include above -->
689    <!--#include virtual="/server/footer.html" -->
690    <div id="footer" role="contentinfo">
691    <div class="unprintable">
692    
693    <p>Please send general FSF &amp; GNU inquiries to
694    <a href="mailto:gnu@gnu.org">&lt;gnu@gnu.org&gt;</a>.
695    There are also <a href="/contact/">other ways to contact</a>
696    the FSF.  Broken links and other corrections or suggestions can be sent
697    to <a href="mailto:webmasters@gnu.org">&lt;webmasters@gnu.org&gt;</a>.</p>
698    
699    <p><!-- TRANSLATORS: Ignore the original text in this paragraph,
700            replace it with the translation of these two:
701    
702            We work hard and do our best to provide accurate, good quality
703            translations.  However, we are not exempt from imperfection.
704            Please send your comments and general suggestions in this regard
705            to <a href="mailto:web-translators@gnu.org">
706            &lt;web-translators@gnu.org&gt;</a>.</p>
707    
708            <p>For information on coordinating and contributing translations of
709            our web pages, see <a
710            href="/server/standards/README.translations.html">Translations
711            README</a>. -->
712    Please see the <a
713    href="/server/standards/README.translations.html">Translations
714    README</a> for information on coordinating and contributing translations
715    of this article.</p>
716  </div>  </div>
717    
718    <!-- Regarding copyright, in general, standalone pages (as opposed to
719         files generated as part of manuals) on the GNU web server should
720         be under CC BY-ND 4.0.  Please do NOT change or remove this
721         without talking with the webmasters or licensing team first.
722         Please make sure the copyright date is consistent with the
723         document.  For web pages, it is ok to list just the latest year the
724         document was modified, or published.
725        
726         If you wish to list earlier years, that is ok too.
727         Either "2001, 2002, 2003" or "2001-2003" are ok for specifying
728         years, as long as each year in the range is in fact a copyrightable
729         year, i.e., a year in which the document was published (including
730         being publicly visible on the web or in a revision control system).
731        
732         There is more detail about copyright years in the GNU Maintainers
733         Information document, www.gnu.org/prep/maintain. -->
734    
735    <p>Copyright &copy; 1996-2002, 2004-2019, 2021
736    Free Software Foundation, Inc.</p>
737    
738    <p>This page is licensed under a <a rel="license"
739    href="http://creativecommons.org/licenses/by-nd/4.0/">Creative
740    Commons Attribution-NoDerivatives 4.0 International License</a>.</p>
741    
742    <!--#include virtual="/server/bottom-notes.html" -->
743    
744    <p class="unprintable">Updated:
745    <!-- timestamp start -->
746    $Date$
747    <!-- timestamp end -->
748    </p>
749    </div>
750    </div><!-- for class="inner", starts in the banner include -->
751  </body>  </body>
752  </html>  </html>

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