/[www]/www/philosophy/free-sw.html
ViewVC logotype

Diff of /www/philosophy/free-sw.html

Parent Directory Parent Directory | Revision Log Revision Log | View Patch Patch

revision 1.3 by paulv, Mon Mar 26 20:47:00 2001 UTC revision 1.157 by rms, Sat Mar 31 00:52:50 2018 UTC
# Line 1  Line 1 
1  <!DOCTYPE html PUBLIC "-//IETF//DTD HTML 2.0//EN">  <!--#include virtual="/server/header.html" -->
2  <HTML>  <!-- Parent-Version: 1.84 -->
3  <HEAD>  <title>What is free software?
4  <TITLE>The Free Software Definition - GNU Project - Free Software Foundation (FSF)</TITLE>  - GNU Project - Free Software Foundation</title>
5  <LINK REV="made" HREF="mailto:webmasters@www.gnu.org">  
6  </HEAD>  <meta http-equiv="Keywords" content="GNU, FSF, Free Software Foundation, Linux, Emacs, GCC, Unix, Free Software, Operating System, GNU Kernel, HURD, GNU HURD, Hurd" />
7  <BODY BGCOLOR="#FFFFFF" TEXT="#000000" LINK="#1F00FF" ALINK="#FF0000" VLINK="#9900DD">  <meta http-equiv="Description" content="Since 1983, developing the free Unix style operating system GNU, so that computer users can have the freedom to share and improve the software they use." />
8  <H3>The Free Software Definition</H3>  
9    <!--#include virtual="/philosophy/po/free-sw.translist" -->
10  <A HREF="/graphics/philosophicalgnu.html"><IMG SRC="/graphics/philosophical-gnu-sm.jpg"  <!--#include virtual="/server/banner.html" -->
11     ALT=" [image of a Philosophical Gnu] "  
12     WIDTH="160" HEIGHT="200"></A>  <h2>What is free software?</h2>
13    
14  [  <blockquote class="note" id="fsf-licensing"><p style="font-size: 80%">
15    <A HREF="/philosophy/free-sw.nl.html">Dutch</A>  Have a question about free software licensing not answered here?
16  | <A HREF="/philosophy/free-sw.html">English</A>  See our other <a href="http://www.fsf.org/licensing">licensing resources</a>,
17  | <A HREF="/philosophy/free-sw.fr.html">French</A>  and if necessary contact the FSF Compliance Lab
18  | <A HREF="/philosophy/free-sw.it.html">Italian</A>  at <a href="mailto:licensing@fsf.org">licensing@fsf.org</a>.</p>
19  | <A HREF="/philosophy/free-sw.ja.html">Japanese</A>  </blockquote>
20  | <A HREF="/philosophy/free-sw.ko.html">Korean</A>  
21  | <A HREF="/philosophy/free-sw.no.html">Norwegian</A>  <h3>The Free Software Definition</h3>
22  | <A HREF="/philosophy/free-sw.pt.html">Portuguese</A>  
23  | <A HREF="/philosophy/free-sw.ru.html">Russian</A>  <blockquote>
24  | <A HREF="/philosophy/free-sw.es.html">Spanish</A>  <p>
25  | <A HREF="/philosophy/free-sw.tr.html">Turkish</A>  The free software definition presents the criteria for whether a
26  ]  particular software program qualifies as free software.  From time to
27  <P>  time we revise this definition, to clarify it or to resolve questions
28    about subtle issues.  See the <a href="#History">History section</a>
29  We maintain this free software definition to show clearly what must be  below for a list of changes that affect the definition of free
30  true about a particular software program for it to be considered  software.
31  ``free software''.  </p>
32    
33  <P>  <p>
34    &ldquo;Open source&rdquo; is something different: it has a very
35  ``Free software'' is a matter of liberty, not price.  To understand the  different philosophy based on different values.  Its practical
36  concept, you should think of ``free'' as in ``free speech,'' not as in  definition is different too, but nearly all open source programs are
37  ``free beer.''  in fact free.  We explain the
38  <P>  difference <a href="/philosophy/open-source-misses-the-point.html">here</a>.
39  ``Free software'' refers to the users' freedom to run, copy,  </p>
40  distribute, study, change and improve the software.  More precisely,  </blockquote>
41  it refers to four kinds of freedom, for the users of the software:  
42  <P>  <p>
43    &ldquo;Free software&rdquo; means software that respects users'
44  <UL>  freedom and community.  Roughly, it means that <b>the users have the
45    <LI>The freedom to run the program, for any purpose (freedom 0).  freedom to run, copy, distribute, study, change and improve the
46    <LI>The freedom to study how the program works, and adapt it to your needs  software</b>.  Thus, &ldquo;free software&rdquo; is a matter of
47        (freedom 1).   Access to the source code is a precondition for this.  liberty, not price.  To understand the concept, you should think of
48    <LI>The freedom to redistribute copies so you can help your neighbor  &ldquo;free&rdquo; as in &ldquo;free speech,&rdquo; not as in
49    &ldquo;free beer&rdquo;.  We sometimes call it &ldquo;libre
50    software,&rdquo; borrowing the French or Spanish word for
51    &ldquo;free&rdquo; as in freedom, to show we do not mean the software
52    is gratis.
53    </p>
54    
55    <p>
56    We campaign for these freedoms because everyone deserves them.  With
57    these freedoms, the users (both individually and collectively) control
58    the program and what it does for them.  When users don't control the
59    program, we call it a &ldquo;nonfree&rdquo; or
60    &ldquo;proprietary&rdquo; program.  The nonfree program controls the
61    users, and the developer controls the program; this makes the
62    program <a href="/philosophy/free-software-even-more-important.html">
63    an instrument of unjust power</a>.
64    </p>
65    
66    <h4> The four essential freedoms</h4>
67    
68    <p>
69    A program is free software if the program's users have the
70    four essential freedoms:
71    </p>
72    
73    <ul>
74      <li>The freedom to run the program as you wish,
75          for any purpose (freedom 0).</li>
76      <li>The freedom to study how the program works, and change it so it
77          does your computing as you wish (freedom 1). Access to the source
78          code is a precondition for this.
79      </li>
80      <li>The freedom to redistribute copies so you can help others
81        (freedom 2).        (freedom 2).
82    <LI>The freedom to improve the program, and release your improvements    </li>
83       to the public, so that the whole community benefits.    <li>The freedom to distribute copies of your modified versions
84        (freedom 3).   Access to the source code is a precondition for this.        to others (freedom 3).  By doing this you can give the whole
85  </UL>        community a chance to benefit from your changes.
86          Access to the source code is a precondition for this.
87  <P>    </li>
88  A program is free software if users have all of these freedoms.  </ul>
89  Thus, you should be free to redistribute copies, either with or  
90  without modifications, either gratis or charging a fee for  <p>
91  distribution, to <A HREF="#exportcontrol">anyone anywhere</A>.  Being  A program is free software if it gives users adequately all of these
92  free to do these things means (among other things) that you do not  freedoms.  Otherwise, it is nonfree.  While we can distinguish various
93  have to ask or pay for permission.  nonfree distribution schemes in terms of how far they fall short of
94    being free, we consider them all equally unethical.</p>
95    
96    <p>In any given scenario, these freedoms must apply to whatever code
97    we plan to make use of, or lead others to make use of.  For instance,
98    consider a program A which automatically launches a program B to
99    handle some cases.  If we plan to distribute A as it stands, that
100    implies users will need B, so we need to judge whether both A and B
101    are free.  However, if we plan to modify A so that it doesn't use B,
102    only A needs to be free; B is not pertinent to that plan.</p>
103    
104    <p>
105    &ldquo;Free software&rdquo; does not mean &ldquo;noncommercial&rdquo;.  A free
106    program must be available for commercial use, commercial development,
107    and commercial distribution.  Commercial development of free software
108    is no longer unusual; such free commercial software is very important.
109    You may have paid money to get copies of free software, or you may have
110    obtained copies at no charge.  But regardless of how you got your copies,
111    you always have the freedom to copy and change the software, even to
112    <a href="/philosophy/selling.html">sell copies</a>.
113    </p>
114    
115    <p>The rest of this page clarifies certain points about what makes
116    specific freedoms adequate or not.</p>
117    
118    <h4>The freedom to run the program as you wish</h4>
119    
120    <p>
121    The freedom to run the program means the freedom for any kind of person
122    or organization to use it on any kind of computer system, for any kind of
123    overall job and purpose, without being required to communicate about it
124    with the developer or any other specific entity.  In this freedom, it is
125    the <em>user's</em> purpose that matters, not the <em>developer's</em>
126    purpose; you as a user are free to run the program for your purposes,
127    and if you distribute it to someone else, she is then free to run it
128    for her purposes, but you are not entitled to impose your purposes on her.
129    </p>
130    
131    <p>
132    The freedom to run the program as you wish means that you are not
133    forbidden or stopped from making it run.  This has nothing to do with what
134    functionality the program has, whether it is technically capable of
135    functioning in any given environment, or whether it is useful for any
136    particular computing activity.</p>
137    
138    <h4>The freedom to study the source code and make changes</h4>
139    
140    <p>
141    In order for freedoms 1 and 3 (the freedom to make changes and the
142    freedom to publish the changed versions) to be meaningful, you must have
143    access to the source code of the program.  Therefore, accessibility of
144    source code is a necessary condition for free software.  Obfuscated
145    &ldquo;source code&rdquo; is not real source code and does not count
146    as source code.
147    </p>
148    
149    <p>
150    Freedom 1 includes the freedom to use your changed version in place of
151    the original.  If the program is delivered in a product designed to
152    run someone else's modified versions but refuse to run yours &mdash; a
153    practice known as &ldquo;tivoization&rdquo; or &ldquo;lockdown&rdquo;,
154    or (in its practitioners' perverse terminology) as &ldquo;secure
155    boot&rdquo; &mdash; freedom 1 becomes an empty pretense rather than a
156    practical reality.  These binaries are not free
157    software even if the source code they are compiled from is free.
158    </p>
159    
160    <p>
161    One important way to modify a program is by merging in available free
162    subroutines and modules.  If the program's license says that you
163    cannot merge in a suitably licensed existing module &mdash; for instance, if it
164    requires you to be the copyright holder of any code you add &mdash; then the
165    license is too restrictive to qualify as free.
166    </p>
167    
168    <p>
169    Whether a change constitutes an improvement is a subjective matter.
170    If your right to modify a program is limited, in substance, to changes that
171    someone else considers an improvement, that program is not free.
172    </p>
173    
174    <h4>The freedom to redistribute if you wish: basic requirements</h4>
175    
176    <p>Freedom to distribute (freedoms 2 and 3) means you are free to
177    redistribute copies, either with or without modifications, either
178    gratis or charging a fee for distribution, to
179    <a href="#exportcontrol">anyone anywhere</a>.  Being free to do these
180    things means (among other things) that you do not have to ask or pay
181    for permission to do so.
182    </p>
183    
184  <P>  <p>
185  You should also have the freedom to make modifications and use them  You should also have the freedom to make modifications and use them
186  privately in your own work or play, without even mentioning that they  privately in your own work or play, without even mentioning that they
187  exist.  If you do publish your changes, you should not be required to  exist.  If you do publish your changes, you should not be required to
188  notify anyone in particular, or in any particular way.  notify anyone in particular, or in any particular way.
189    </p>
190    
191  <P>  <p>
192  The freedom to use a program means the freedom for any kind of person  Freedom 3 includes the freedom to release your modified versions
193  or organization to use it on any kind of computer system, for any kind  as free software.  A free license may also permit other ways of
194  of overall job, and without being required to communicate subsequently  releasing them; in other words, it does not have to be
195  with the developer or any other specific entity.  a <a href="/copyleft/copyleft.html">copyleft</a> license.  However, a
196    license that requires modified versions to be nonfree does not qualify
197    as a free license.
198    </p>
199    
200  <P>  <p>
201  The freedom to redistribute copies must include binary or executable  The freedom to redistribute copies must include binary or executable
202  forms of the program, as well as source code.  (It is ok if there is  forms of the program, as well as source code, for both modified and
203  no way to produce a binary or executable form, but people must have  unmodified versions.  (Distributing programs in runnable form is necessary
204  the freedom to redistribute such forms should they find a way to make  for conveniently installable free operating systems.)  It is OK if there
205  them.)  is no way to produce a binary or executable form for a certain program
206    (since some languages don't support that feature), but you must have the
207  <P>  freedom to redistribute such forms should you find or develop a way to
208  In order for the freedoms to make changes, and to publish improved  make them.
209  versions, to be meaningful, you must have access to the source code of  </p>
210  the program.  Therefore, accessibility of source code is a necessary  
211  condition for free software.  <h4>Copyleft</h4>
   
 <P>  
 In order for these freedoms to be real, they must be irrevocable as  
 long as you do nothing wrong; if the developer of the software has the  
 power to revoke the license, without your doing anything to give  
 cause, the software is not free.  
212    
213  <P>  <p>
214  However, certain kinds of rules about the manner of distributing free  Certain kinds of rules about the manner of distributing free
215  software are acceptable, when they don't conflict with the central  software are acceptable, when they don't conflict with the central
216  freedoms.  For example, copyleft (very simply stated) is the rule that  freedoms.  For example, <a href="/copyleft/copyleft.html">copyleft</a>
217  when redistributing the program, you cannot add restrictions to deny  (very simply stated) is the rule that when redistributing the program,
218  other people the central freedoms.  This rule does not conflict with  you cannot add restrictions to deny other people the central freedoms.
219  the central freedoms; rather it protects them.  This rule does not conflict with the central freedoms; rather it
220    protects them.
221  <P>  </p>
222  Thus, you may have paid money to get copies of GNU software, or you  
223  may have obtained copies at no charge.  But regardless of how you got  <p>
224  your copies, you always have the freedom to copy and change the  In the GNU project, we use copyleft to protect the four freedoms
225  software, even to <A HREF="/philosophy/selling.html">sell copies</A>.  legally for everyone.  We believe there are important reasons why
226    <a href="/philosophy/pragmatic.html">it is better to use
227  <P>  copyleft</a>.  However,
228  ``Free software'' does not mean ``non-commercial''.  A free program  <a href="/philosophy/categories.html#Non-CopyleftedFreeSoftware">
229  must be available for commercial use.  Commercial development of free  noncopylefted free software</a> is ethical
230  software is no longer unusual; such programs are free commercial  too.  See <a href="/philosophy/categories.html">Categories of Free
231  software.  Software</a> for a description of how &ldquo;free software,&rdquo;
232    &ldquo;copylefted software&rdquo; and other categories of software
233    relate to each other.
234    </p>
235    
236    <h4>Rules about packaging and distribution details</h4>
237    
238    <p>
239    Rules about how to package a modified version are acceptable,
240    if they don't substantively limit your freedom to release modified
241    versions, or your freedom to make and use modified versions privately.
242    Thus, it is acceptable for the license to require that you change the
243    name of the modified version, remove a logo, or identify your
244    modifications as yours.  As long as these requirements are not so
245    burdensome that they effectively hamper you from releasing your
246    changes, they are acceptable; you're already making other changes to
247    the program, so you won't have trouble making a few more.
248    </p>
249    
250    <p>
251    Rules that &ldquo;if you make your version available in this way, you
252    must make it available in that way also&rdquo; can be acceptable too,
253    on the same condition.  An example of such an acceptable rule is one
254    saying that if you have distributed a
255    modified version and a previous developer asks for a copy of it, you
256    must send one.  (Note that such a rule still leaves you the choice of
257    whether to distribute your version at all.)  Rules that require release
258    of source code to the users for versions that you put into public use
259    are also acceptable.
260    </p>
261    
262    <p>
263    A special issue arises when a license requires changing the name by
264    which the program will be invoked from other programs.  That
265    effectively hampers you from releasing your changed version so that it
266    can replace the original when invoked by those other programs.  This
267    sort of requirement is acceptable only if there's a suitable aliasing
268    facility that allows you to specify the original program's name as an
269    alias for the modified version.</p>
270    
271    <h4>Export regulations</h4>
272    
273    <p>
274    Sometimes government <a id="exportcontrol">export control regulations</a>
275    and trade sanctions can constrain your freedom to distribute copies of
276    programs internationally.  Software developers do not have the power to
277    eliminate or override these restrictions, but what they can and must do
278    is refuse to impose them as conditions of use of the program.  In this
279    way, the restrictions will not affect activities and people outside the
280    jurisdictions of these governments.  Thus, free software licenses
281    must not require obedience to any nontrivial export regulations as a
282    condition of exercising any of the essential freedoms.
283    </p>
284    
285    <p>
286    Merely mentioning the existence of export regulations, without making
287    them a condition of the license itself, is acceptable since it does
288    not restrict users.  If an export regulation is actually trivial for
289    free software, then requiring it as a condition is not an actual
290    problem; however, it is a potential problem, since a later change in
291    export law could make the requirement nontrivial and thus render the
292    software nonfree.
293    </p>
294    
295    <h4>Legal considerations</h4>
296    
297    <p>
298    In order for these freedoms to be real, they must be permanent and
299    irrevocable as long as you do nothing wrong; if the developer of the
300    software has the power to revoke the license, or retroactively add
301    restrictions to its terms, without your doing anything wrong to give
302    cause, the software is not free.
303    </p>
304    
305  <P>  <p>
306  Rules about how to package a modified version are acceptable, if they  A free license may not require compliance with the license of a
307  don't effectively block your freedom to release modified versions.  nonfree program.  Thus, for instance, if a license requires you to
308  Rules that ``if you make the program available in this way, you must  comply with the licenses of &ldquo;all the programs you use&rdquo;, in
309  make it available in that way also'' can be acceptable too, on the  the case of a user that runs nonfree programs this would require
310  same condition.  (Note that such a rule still leaves you the choice of  compliance with the licenses of those nonfree programs; that makes the
311  whether to publish the program or not.)  license nonfree.
312    </p>
313  <P>  
314  In the GNU project, we use <A HREF="/copyleft/copyleft.html">  <p>
315  ``copyleft''</A> to protect these freedoms legally for everyone.  But  It is acceptable for a free license to specify which jurisdiction's
316  <A HREF="/philosophy/categories.html#Non-CopyleftedFreeSoftware">  law applies, or where litigation must be done, or both.
317  non-copylefted free software</A> also exists.  We believe there are  </p>
318  important reasons why <A HREF="/philosophy/pragmatic.html"> it is  
319  better to use copyleft</A>, but if your program is non-copylefted free  <h4>Contract-based licenses</h4>
320  software, we can still use it.  
321    <p>
322  <P>  Most free software licenses are based on copyright, and there are limits
323  See <A HREF="/philosophy/categories.html">Categories of Free Software  on what kinds of requirements can be imposed through copyright.  If a
324         (18k characters)</A>  copyright-based license respects freedom in the ways described above, it
325  for a description of how ``free software,'' ``copylefted software'' and  is unlikely to have some other sort of problem that we never anticipated
326  other categories of software relate to each other.  (though this does happen occasionally).  However, some free software
327    licenses are based on contracts, and contracts can impose a much larger
328  <P>  range of possible restrictions.  That means there are many possible ways
329  Sometimes government <A NAME="exportcontrol">export control  such a license could be unacceptably restrictive and nonfree.
330  regulations</A> and trade sanctions can constrain your freedom to  </p>
331  distribute copies of programs internationally.  Software developers do  
332  not have the power to eliminate or override these restrictions, but  <p>
333  what they can and must do is refuse to impose them as conditions of  We can't possibly list all the ways that might happen.  If a
334  use of the program.  In this way, the restrictions will not affect  contract-based license restricts the user in an unusual way that
335  activities and people outside the jurisdictions of these governments.  copyright-based licenses cannot, and which isn't mentioned here as
336    legitimate, we will have to think about it, and we will probably conclude
337  <P>  it is nonfree.
338  When talking about free software, it is best to avoid using terms like  </p>
339  ``give away'' or ``for free'', because those terms imply that the  
340  issue is about price, not freedom.  Some common terms such as  <h4>Use the right words when talking about free software</h4>
341  ``piracy'' embody opinions we hope you won't endorse.  See <A  
342  HREF="/philosophy/words-to-avoid.html">Confusing Words and Phrases  <p>
343  that are Worth Avoiding</A> for a discussion of these terms.  When talking about free software, it is best to avoid using terms
344  We also have a list of <A HREF="/philosophy/fs-translations.html">translations  like &ldquo;give away&rdquo; or &ldquo;for free,&rdquo; because those terms imply that
345  of "free software"</A> into various languages.  the issue is about price, not freedom.  Some common terms such
346    as &ldquo;piracy&rdquo; embody opinions we hope you won't endorse.  See
347    <a href="/philosophy/words-to-avoid.html">Confusing Words and Phrases that
348    are Worth Avoiding</a> for a discussion of these terms.  We also have
349    a list of proper <a href="/philosophy/fs-translations.html">translations of
350    &ldquo;free software&rdquo;</a> into various languages.
351    </p>
352    
353  <P>  <h4>How we interpret these criteria</h4>
354    
355    <p>
356  Finally, note that criteria such as those stated in this free software  Finally, note that criteria such as those stated in this free software
357  definition require careful thought for their interpretation.  To  definition require careful thought for their interpretation.  To decide
358  decide whether a specific software license qualifies as a free  whether a specific software license qualifies as a free software license,
359  software license, we judge it based on these criteria to determine  we judge it based on these criteria to determine whether it fits their
360  whether it fits their spirit as well as the precise words.  If a  spirit as well as the precise words.  If a license includes unconscionable
361  license includes unconscionable restrictions, we reject it, even if we  restrictions, we reject it, even if we did not anticipate the issue
362  did not anticipate the issue in these criteria.  Sometimes a license  in these criteria.  Sometimes a license requirement raises an issue
363  requirement raises an issue that calls for extensive thought before we  that calls for extensive thought, including discussions with a lawyer,
364  can decide if the requirement is acceptable, including discussions  before we can decide if the requirement is acceptable.  When we reach
365  with a lawyer.  When we reach a conclusion, we sometimes update these  a conclusion about a new issue, we often update these criteria to make
366  criteria to make it easier to see why certain licenses do or don't  it easier to see why certain licenses do or don't qualify.
367  qualify.  </p>
368    
369  <P>  <h4>Get help with free licenses</h4>
370    
371  If you are interested in whether a specific license qualifies as a  <p>
372  free software license, see our <A  If you are interested in whether a specific license qualifies as a free
373  HREF="/philosophy/license-list.html"> list of licenses </A>.  If the  software license, see our <a href="/licenses/license-list.html">list
374  license you are concerned with is not listed there, you can ask us  of licenses</a>.  If the license you are concerned with is not
375  about it by sending us email at <A  listed there, you can ask us about it by sending us email at
376  HREF="mailto:licensing@gnu.org">&lt;licensing@gnu.org&gt;</A>.  <a href="mailto:licensing@gnu.org">&lt;licensing@gnu.org&gt;</a>.
377    </p>
378  <HR>  
379    <p>
380  <H4><A HREF="/philosophy/philosophy.html">Other Texts to Read</A></H4>  If you are contemplating writing a new license, please contact the
381    Free Software Foundation first by writing to that address. The
382  <P>  proliferation of different free software licenses means increased work
383  Another group has started using the term <A  for users in understanding the licenses; we may be able to help you
384  HREF="free-software-for-freedom.html"> open source</A> to mean  find an existing free software license that meets your needs.
385  something close (but not identical) to "free software".  </p>
386    
387  <HR>  <p>
388    If that isn't possible, if you really need a new license, with our
389  Return to <A HREF="/home.html">GNU's home page</A>.  help you can ensure that the license really is a free software license
390  <P>  and avoid various practical problems.
391  FSF &amp; GNU inquiries &amp; questions to  </p>
392  <A HREF="mailto:gnu@gnu.org"><EM>gnu@gnu.org</EM></A>.  
393  Other <A HREF="/home.html#ContactInfo">ways to contact</A> the FSF.  <h3 id="beyond-software">Beyond Software</h3>
394  <P>  
395  Comments on these web pages to  <p>
396  <A HREF="mailto:webmasters@www.gnu.org"><EM>webmasters@www.gnu.org</EM></A>,  <a href="/philosophy/free-doc.html">Software manuals must be free</a>,
397  send other questions to  for the same reasons that software must be free, and because the
398  <A HREF="mailto:gnu@gnu.org"><EM>gnu@gnu.org</EM></A>.  manuals are in effect part of the software.
399  <P>  </p>
400  Copyright (C) 1996, 1997, 1998, 1999, 2000, 2001 Free Software Foundation, Inc.,  
401  59 Temple Place - Suite 330, Boston, MA  02111,  USA  <p>
402  <P>  The same arguments also make sense for other kinds of works of
403  Verbatim copying and distribution of this entire article is  practical use &mdash; that is to say, works that embody useful knowledge,
404  permitted in any medium, provided this notice is preserved.<P>  such as educational works and reference
405  Updated:  works.  <a href="http://wikipedia.org">Wikipedia</a> is the best-known
406    example.
407    </p>
408    
409    <p>
410    Any kind of work <em>can</em> be free, and the definition of free software
411    has been extended to a definition of <a href="http://freedomdefined.org/">
412    free cultural works</a> applicable to any kind of works.
413    </p>
414    
415    <h3 id="open-source">Open Source?</h3>
416    
417    <p>
418    Another group uses the term &ldquo;open source&rdquo; to mean
419    something close (but not identical) to &ldquo;free software&rdquo;.  We
420    prefer the term &ldquo;free software&rdquo; because, once you have heard that
421    it refers to freedom rather than price, it calls to mind freedom.  The
422    word &ldquo;open&rdquo; <a href="/philosophy/open-source-misses-the-point.html">
423    never refers to freedom</a>.
424    </p>
425    
426    <h3 id="History">History</h3>
427    
428    <p>From time to time we revise this Free Software Definition.  Here is
429    the list of substantive changes, along with links to show exactly what
430    was changed.</p>
431    
432    <ul>
433    
434    <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
435    1.153</a>: Clarify that freedom to run the program means nothing stops
436    you from making it run.</li>
437    
438    <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
439    1.141</a>: Clarify which code needs to be free.</li>
440    
441    <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
442    1.135</a>: Say each time that freedom 0 is the freedom to run the program
443    as you wish.</li>
444    
445    <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
446    1.134</a>: Freedom 0 is not a matter of the program's functionality.</li>
447    
448    <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
449    1.131</a>: A free license may not require compliance with a nonfree license
450    of another program.</li>
451    
452    <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
453    1.129</a>: State explicitly that choice of law and choice of forum
454    specifications are allowed.  (This was always our policy.)</li>
455    
456    <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
457    1.122</a>: An export control requirement is a real problem if the
458    requirement is nontrivial; otherwise it is only a potential problem.</li>
459    
460    <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
461    1.118</a>: Clarification: the issue is limits on your right to modify,
462    not on what modifications you have made.  And modifications are not limited
463    to &ldquo;improvements&rdquo;</li>
464    
465    <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
466    1.111</a>: Clarify 1.77 by saying that only
467    retroactive <em>restrictions</em> are unacceptable.  The copyright
468    holders can always grant additional <em>permission</em> for use of the
469    work by releasing the work in another way in parallel.</li>
470    
471    <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
472    1.105</a>: Reflect, in the brief statement of freedom 1, the point
473    (already stated in version 1.80) that it includes really using your modified
474    version for your computing.</li>
475    
476    <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
477    1.92</a>: Clarify that obfuscated code does not qualify as source code.</li>
478    
479    <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
480    1.90</a>: Clarify that freedom 3 means the right to distribute copies
481    of your own modified or improved version, not a right to participate
482    in someone else's development project.</li>
483    
484    <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
485    1.89</a>: Freedom 3 includes the right to release modified versions as
486    free software.</li>
487    
488    <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
489    1.80</a>: Freedom 1 must be practical, not just theoretical;
490    i.e., no tivoization.</li>
491    
492    <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
493    1.77</a>: Clarify that all retroactive changes to the license are
494    unacceptable, even if it's not described as a complete
495    replacement.</li>
496    
497    <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
498    1.74</a>: Four clarifications of points not explicit enough, or stated
499    in some places but not reflected everywhere:
500    <ul>
501    <li>"Improvements" does not mean the license can
502    substantively limit what kinds of modified versions you can release.
503    Freedom 3 includes distributing modified versions, not just changes.</li>
504    <li>The right to merge in existing modules
505    refers to those that are suitably licensed.</li>
506    <li>Explicitly state the conclusion of the point about export controls.</li>
507    <li>Imposing a license change constitutes revoking the old license.</li>
508    </ul>
509    </li>
510    
511    <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
512    1.57</a>: Add &quot;Beyond Software&quot; section.</li>
513    
514    <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
515    1.46</a>: Clarify whose purpose is significant in the freedom to run
516    the program for any purpose.</li>
517    
518    <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
519    1.41</a>: Clarify wording about contract-based licenses.</li>
520    
521    <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
522    1.40</a>: Explain that a free license must allow to you use other
523    available free software to create your modifications.</li>
524    
525    <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
526    1.39</a>: Note that it is acceptable for a license to require you to
527    provide source for versions of the software you put into public
528    use.</li>
529    
530    <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
531    1.31</a>: Note that it is acceptable for a license to require you to
532    identify yourself as the author of modifications.  Other minor
533    clarifications throughout the text.</li>
534    
535    <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
536    1.23</a>: Address potential problems related to contract-based
537    licenses.</li>
538    
539    <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
540    1.16</a>: Explain why distribution of binaries is important.</li>
541    
542    <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
543    1.11</a>: Note that a free license may require you to send a copy of
544    versions you distribute to previous developers on request.</li>
545    
546    </ul>
547    
548    <p>There are gaps in the version numbers shown above because there are
549    other changes in this page that do not affect the definition or its
550    interpretations.  For instance, the list does not include changes in
551    asides, formatting, spelling, punctuation, or other parts of the page.
552    You can review the complete list of changes to the page through
553    the <a href="http://web.cvs.savannah.gnu.org/viewvc/www/philosophy/free-sw.html?root=www&amp;view=log">cvsweb
554    interface</a>.</p>
555    
556    
557    </div><!-- for id="content", starts in the include above -->
558    <!--#include virtual="/server/footer.html" -->
559    <div id="footer">
560    <div class="unprintable">
561    
562    <p>Please send general FSF &amp; GNU inquiries to
563    <a href="mailto:gnu@gnu.org">&lt;gnu@gnu.org&gt;</a>.
564    There are also <a href="/contact/">other ways to contact</a>
565    the FSF.  Broken links and other corrections or suggestions can be sent
566    to <a href="mailto:webmasters@gnu.org">&lt;webmasters@gnu.org&gt;</a>.</p>
567    
568    <p><!-- TRANSLATORS: Ignore the original text in this paragraph,
569            replace it with the translation of these two:
570    
571            We work hard and do our best to provide accurate, good quality
572            translations.  However, we are not exempt from imperfection.
573            Please send your comments and general suggestions in this regard
574            to <a href="mailto:web-translators@gnu.org">
575            &lt;web-translators@gnu.org&gt;</a>.</p>
576    
577            <p>For information on coordinating and submitting translations of
578            our web pages, see <a
579            href="/server/standards/README.translations.html">Translations
580            README</a>. -->
581    Please see the <a
582    href="/server/standards/README.translations.html">Translations
583    README</a> for information on coordinating and submitting translations
584    of this article.</p>
585    </div>
586    
587    <!-- Regarding copyright, in general, standalone pages (as opposed to
588         files generated as part of manuals) on the GNU web server should
589         be under CC BY-ND 4.0.  Please do NOT change or remove this
590         without talking with the webmasters or licensing team first.
591         Please make sure the copyright date is consistent with the
592         document.  For web pages, it is ok to list just the latest year the
593         document was modified, or published.
594        
595         If you wish to list earlier years, that is ok too.
596         Either "2001, 2002, 2003" or "2001-2003" are ok for specifying
597         years, as long as each year in the range is in fact a copyrightable
598         year, i.e., a year in which the document was published (including
599         being publicly visible on the web or in a revision control system).
600        
601         There is more detail about copyright years in the GNU Maintainers
602         Information document, www.gnu.org/prep/maintain. -->
603    
604    <p>Copyright &copy; 1996, 2002, 2004-2007, 2009-2018
605    Free Software Foundation, Inc.</p>
606    
607    <p>This page is licensed under a <a rel="license"
608    href="http://creativecommons.org/licenses/by-nd/4.0/">Creative
609    Commons Attribution-NoDerivatives 4.0 International License</a>.</p>
610    
611    <!--#include virtual="/server/bottom-notes.html" -->
612    
613    <p class="unprintable">Updated:
614  <!-- timestamp start -->  <!-- timestamp start -->
615  $Date$ $Author$  $Date$
616  <!-- timestamp end -->  <!-- timestamp end -->
617  <HR>  </p>
618  </BODY>  </div>
619  </HTML>  </div>
620    </body>
621    </html>

Legend:
Removed from v.1.3  
changed lines
  Added in v.1.157

savannah-hackers-public@gnu.org
ViewVC Help
Powered by ViewVC 1.1.26