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revision 1.79 by rms, Wed May 27 23:03:29 2009 UTC revision 1.91 by karl, Tue Mar 9 22:51:49 2010 UTC
# Line 20  the <a href="#History">History section</ Line 20  the <a href="#History">History section</
20  </p>  </p>
21    
22  <p>  <p>
23  <q>Free software</q> is a matter of liberty, not price.  To understand  &ldquo;Free software&rdquo; is a matter of liberty, not price.  To understand
24  the concept, you should think of <q>free</q> as in <q>free speech,</q>  the concept, you should think of &ldquo;free&rdquo; as in &ldquo;free speech,&rdquo;
25  not as in <q>free beer.</q>  not as in &ldquo;free beer.&rdquo;
26  </p>  </p>
27    
28  <p>  <p>
29  Free software is a matter of the users' freedom to run, copy, distribute,  Free software is a matter of the users' freedom to run, copy, distribute,
30  study, change and improve the software.  More precisely, it refers to  study, change and improve the software.  More precisely, it means that the
31  four kinds of freedom, for the users of the software:  program's users have the four essential freedoms:
32  </p>  </p>
33    
34  <ul>  <ul>
35    <li>The freedom to run the program, for any purpose (freedom 0).</li>    <li>The freedom to run the program, for any purpose (freedom 0).</li>
36    <li>The freedom to study how the program works, and adapt it to    <li>The freedom to study how the program works, and change it to make
37        your needs (freedom 1). Access to the source code is a precondition        it do what you wish (freedom 1). Access to the source code is a
38        for this.        precondition for this.
39    </li>    </li>
40    <li>The freedom to redistribute copies so you can help your neighbor    <li>The freedom to redistribute copies so you can help your neighbor
41        (freedom 2).        (freedom 2).
42    </li>    </li>
43    <li>The freedom to improve the program, and release your improvements    <li>The freedom to distribute copies of your modified versions
44        (and modified versions in general)        to others (freedom 3).  By doing this you can give the whole
45        to the public, so that the whole community benefits (freedom 3).        community a chance to benefit from your changes.
46        Access to the source code is a precondition for this.        Access to the source code is a precondition for this.
47    </li>    </li>
48  </ul>  </ul>
# Line 53  you should be free to redistribute copie Line 53  you should be free to redistribute copie
53  modifications, either gratis or charging a fee for distribution, to  modifications, either gratis or charging a fee for distribution, to
54  <a href="#exportcontrol">anyone anywhere</a>.  Being free to do these  <a href="#exportcontrol">anyone anywhere</a>.  Being free to do these
55  things means (among other things) that you do not have to ask or pay  things means (among other things) that you do not have to ask or pay
56  for permission.  for permission to do so.
57  </p>  </p>
58    
59  <p>  <p>
# Line 69  or organization to use it on any kind of Line 69  or organization to use it on any kind of
69  overall job and purpose, without being required to communicate about it  overall job and purpose, without being required to communicate about it
70  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
71  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>
72  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,
73  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
74  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.
75  </p>  </p>
# Line 78  for her purposes, but you are not entitl Line 78  for her purposes, but you are not entitl
78  The freedom to redistribute copies must include binary or executable  The freedom to redistribute copies must include binary or executable
79  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
80  unmodified versions.  (Distributing programs in runnable form is necessary  unmodified versions.  (Distributing programs in runnable form is necessary
81  for conveniently installable free operating systems.)  It is ok if there  for conveniently installable free operating systems.)  It is OK if there
82  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
83  (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
84  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
# Line 86  make them. Line 86  make them.
86  </p>  </p>
87    
88  <p>  <p>
89  In order for the freedoms to make changes, and to publish improved  In order for freedoms 1 and 3 (the freedom to make changes and the
90  versions, to be meaningful, you must have access to the source code of  freedom to publish improved versions) to be meaningful, you must have
91  the program.  Therefore, accessibility of source code is a necessary  access to the source code of the program.  Therefore, accessibility of
92  condition for free software.  source code is a necessary condition for free software.
93    </p>
94    
95    <p>
96    Freedom 1 includes the freedom to use your changed version in place of
97    the original.  If the program is delivered in a product designed to
98    run someone else's modified versions but refuse to run yours &mdash;
99    a practice known as &ldquo;tivoization&rdquo; or (through
100    blacklisting) as &ldquo;secure boot&rdquo; &mdash; freedom 1 becomes a
101    theoretical fiction rather than a practical freedom.  This is not
102    sufficient.  In other words, these binaries are not free software
103    even if the source code they are compiled from is free.
104  </p>  </p>
105    
106  <p>  <p>
107  One important way to modify a program is by merging in available free  One important way to modify a program is by merging in available free
108  subroutines and modules.  If the program's license says that you  subroutines and modules.  If the program's license says that you
109  cannot merge in a suitably-licensed existing module, such as if it  cannot merge in a suitably licensed existing module &mdash; for instance, if it
110  requires you to be the copyright holder of any code you add, then the  requires you to be the copyright holder of any code you add &mdash; then the
111  license is too restrictive to qualify as free.  license is too restrictive to qualify as free.
112  </p>  </p>
113    
114  <p>  <p>
115    Freedom 3 includes the freedom to use release your modified versions
116    as free software.  A free license may also permit other ways of
117    releasing them; in other words, it does not have to be
118    a <a href="/copyleft/copyleft.html">copyleft</a> license.  However, a
119    license that requires modified versions to be nonfree does not qualify
120    as a free license.
121    </p>
122    
123    <p>
124  In order for these freedoms to be real, they must be permanent and  In order for these freedoms to be real, they must be permanent and
125  irrevocable as long as you do nothing wrong; if the developer of the  irrevocable as long as you do nothing wrong; if the developer of the
126  software has the power to revoke the license, or retroactively change  software has the power to revoke the license, or retroactively change
# Line 118  the central freedoms; rather it protects Line 138  the central freedoms; rather it protects
138  </p>  </p>
139    
140  <p>  <p>
141  <q>Free software</q> does not mean <q>non-commercial.</q>  A free  &ldquo;Free software&rdquo; does not mean &ldquo;noncommercial.&rdquo;  A free
142  program must be available for commercial use, commercial development,  program must be available for commercial use, commercial development,
143  and commercial distribution.  Commercial development of free software  and commercial distribution.  Commercial development of free software
144  is no longer unusual; such free commercial software is very important.  is no longer unusual; such free commercial software is very important.
# Line 137  someone else considers an improvement, t Line 157  someone else considers an improvement, t
157  <p>  <p>
158  However, rules about how to package a modified version are acceptable, if they  However, rules about how to package a modified version are acceptable, if they
159  don't substantively limit your freedom to release modified versions, or  don't substantively limit your freedom to release modified versions, or
160  your freedom to make and use modified versions privately.  Rules that <q>if  your freedom to make and use modified versions privately.  Rules that &ldquo;if
161  you make your version available in this way, you must make it available in  you make your version available in this way, you must make it available in
162  that way also</q> can be acceptable too, on the same condition.  (Note that  that way also&rdquo; can be acceptable too, on the same condition.  (Note that
163  such a rule still leaves you the choice of whether to publish your version  such a rule still leaves you the choice of whether to publish your version
164  at all.)  Rules that require release of source code to the users for  at all.)  Rules that require release of source code to the users for
165  versions that you put into public use are also acceptable.  It is also  versions that you put into public use are also acceptable.  It is also
166  acceptable for the license to require that, if you have distributed a  acceptable for the license to require that you identify
167  modified version and a previous developer asks for a copy of it, you  your modifications as yours, or that, if you have distributed a modified
168  must send one, or that you identify yourself on your modifications.  version and a previous developer asks for a copy of it, you must send
169    one.
170  </p>  </p>
171    
172  <p>  <p>
173  In the GNU project, we use  In the GNU project, we use
174  <q><a href="/copyleft/copyleft.html">copyleft</a></q>  &ldquo;<a href="/copyleft/copyleft.html">copyleft</a>&rdquo;
175  to protect these freedoms legally for everyone.  But  to protect these freedoms legally for everyone.  But
176  <a href="/philosophy/categories.html#Non-CopyleftedFreeSoftware">non-copylefted  <a href="/philosophy/categories.html#Non-CopyleftedFreeSoftware">non-copylefted
177  free software</a> also exists.  We believe there are important reasons why  free software</a> also exists.  We believe there are important reasons why
178  <a href="/philosophy/pragmatic.html"> it is better to use copyleft</a>,  <a href="/philosophy/pragmatic.html">it is better to use copyleft</a>,
179  but if your program is non-copylefted free software, it is still basically  but if your program is non-copylefted free software, it is still basically
180  ethical.  ethical.
181  </p>  </p>
182    
183  <p>  <p>
184  See <a href="/philosophy/categories.html">Categories of Free Software</a>  See <a href="/philosophy/categories.html">Categories of Free Software</a>
185  for a description of how <q>free software,</q> <q>copylefted software</q>  for a description of how &ldquo;free software,&rdquo; &ldquo;copylefted software&rdquo;
186  and other categories of software relate to each other.  and other categories of software relate to each other.
187  </p>  </p>
188    
# Line 185  is unlikely to have some other sort of p Line 206  is unlikely to have some other sort of p
206  (though this does happen occasionally).  However, some free software  (though this does happen occasionally).  However, some free software
207  licenses are based on contracts, and contracts can impose a much larger  licenses are based on contracts, and contracts can impose a much larger
208  range of possible restrictions.  That means there are many possible ways  range of possible restrictions.  That means there are many possible ways
209  such a license could be unacceptably restrictive and non-free.  such a license could be unacceptably restrictive and nonfree.
210  </p>  </p>
211    
212  <p>  <p>
# Line 193  We can't possibly list all the ways that Line 214  We can't possibly list all the ways that
214  contract-based license restricts the user in an unusual way that  contract-based license restricts the user in an unusual way that
215  copyright-based licenses cannot, and which isn't mentioned here as  copyright-based licenses cannot, and which isn't mentioned here as
216  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
217  it is non-free.  it is nonfree.
218  </p>  </p>
219    
220  <p>  <p>
221  When talking about free software, it is best to avoid using terms  When talking about free software, it is best to avoid using terms
222  like <q>give away</q> or <q>for free,</q> because those terms imply that  like &ldquo;give away&rdquo; or &ldquo;for free,&rdquo; because those terms imply that
223  the issue is about price, not freedom.  Some common terms such  the issue is about price, not freedom.  Some common terms such
224  as <q>piracy</q> embody opinions we hope you won't endorse.  See  as &ldquo;piracy&rdquo; embody opinions we hope you won't endorse.  See
225  <a href="/philosophy/words-to-avoid.html">Confusing Words and Phrases that  <a href="/philosophy/words-to-avoid.html">Confusing Words and Phrases that
226  are Worth Avoiding</a> for a discussion of these terms.  We also have  are Worth Avoiding</a> for a discussion of these terms.  We also have
227  a list of <a href="/philosophy/fs-translations.html">translations of  a list of proper <a href="/philosophy/fs-translations.html">translations of
228  <q>free software</q></a> into various languages.  &ldquo;free software&rdquo;</a> into various languages.
229  </p>  </p>
230    
231  <p>  <p>
# Line 230  listed there, you can ask us about it by Line 251  listed there, you can ask us about it by
251  </p>  </p>
252    
253  <p>  <p>
254  If you are contemplating writing a new license, please contact the FSF  If you are contemplating writing a new license, please contact the
255  by writing to that address. The proliferation of different free software  Free Software Foundation first by writing to that address. The
256  licenses means increased work for users in understanding the licenses;  proliferation of different free software licenses means increased work
257  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
258  meets your needs.  find an existing free software license that meets your needs.
259  </p>  </p>
260    
261  <p>  <p>
262  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
263  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
264  and avoid various practical problems.  and avoid various practical problems.
265  </p>  </p>
266    
# Line 268  free cultural works</a> applicable to an Line 289  free cultural works</a> applicable to an
289  <h2 id="open-source">Open Source?</h2>  <h2 id="open-source">Open Source?</h2>
290    
291  <p>  <p>
292  Another group has started using the term <q>open source</q> to mean  Another group has started using the term &ldquo;open source&rdquo; to mean
293  something close (but not identical) to <q>free software.</q>  We  something close (but not identical) to &ldquo;free software.&rdquo;  We
294  prefer the term <q>free software</q> because, once you have heard that  prefer the term &ldquo;free software&rdquo; because, once you have heard that
295  it refers to freedom rather than price, it calls to mind freedom.  The  it refers to freedom rather than price, it calls to mind freedom.  The
296  word <q>open</q> <a href="/philosophy/open-source-misses-the-point.html">  word &ldquo;open&rdquo; <a href="/philosophy/open-source-misses-the-point.html">
297  never refers to freedom</a>.  never refers to freedom</a>.
298  </p>  </p>
299    
# Line 285  them if they like.</p> Line 306  them if they like.</p>
306    
307  <ul>  <ul>
308    
309    <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
310    1.90</a>: Clarify that freedom 3 means the right to distribute copies
311    of your own modified or improved version, not a right to participate
312    in someone else's development project.</li>
313    
314    <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
315    1.89</a>: Freedom 3 includes the right to release modified versions as
316    free software.</li>
317    
318    <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
319    1.80</a>: Freedom 1 must be practical, not just theoretical;
320    i.e., no tivoization.</li>
321    
322  <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  <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
323  1.77</a>: Clarify that all retroactive changes to the license are  1.77</a>: Clarify that all retroactive changes to the license are
324  unacceptable, even if it's not described as a complete  unacceptable, even if it's not described as a complete
# Line 356  interface</a>.</p> Line 390  interface</a>.</p>
390    
391  <p>  <p>
392  Please send FSF &amp; GNU inquiries to  Please send FSF &amp; GNU inquiries to
393  <a href="mailto:gnu@gnu.org"><em>gnu@gnu.org</em></a>.  <a href="mailto:gnu@gnu.org">&lt;gnu@gnu.org&gt;</a>.
394  There are also <a href="/contact/">other ways to contact</a>  There are also <a href="/contact/">other ways to contact</a>
395  the FSF.  the FSF.
396  <br />  <br />
397  Please send broken links and other corrections or suggestions to  Please send broken links and other corrections or suggestions to
398  <a href="mailto:webmasters@gnu.org"><em>webmasters@gnu.org</em></a>.  <a href="mailto:webmasters@gnu.org">&lt;webmasters@gnu.org&gt;</a>.
399  </p>  </p>
400    
401  <p>  <p>
# Line 373  translations of this article. Line 407  translations of this article.
407    
408  <p>  <p>
409  Copyright &copy; 1996, 1997, 1998, 1999, 2000, 2001, 2002, 2003, 2004,  Copyright &copy; 1996, 1997, 1998, 1999, 2000, 2001, 2002, 2003, 2004,
410  2005, 2006, 2007 Free Software Foundation, Inc.,  2005, 2006, 2007, 2009 Free Software Foundation, Inc.
411  </p>  </p>
 <address>51 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA</address>  
412  <p>Verbatim copying and distribution of this entire article is  <p>Verbatim copying and distribution of this entire article is
413  permitted in any medium without royalty provided this notice is  permitted in any medium without royalty provided this notice is
414  preserved.  preserved.
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