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- GNU Project - Free Software Foundation</title> |
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<h2>What is free software?</h2> |
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<blockquote class="note" id="fsf-licensing"><p style="font-size: 80%"> |
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Have a question about free software licensing not answered here? |
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See our other <a href="http://www.fsf.org/licensing">licensing resources</a>, |
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and if necessary contact the FSF Compliance Lab |
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at <a href="mailto:licensing@fsf.org">licensing@fsf.org</a>.</p> |
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</blockquote> |
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<body> |
<h3>The Free Software Definition</h3> |
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<p><a href="#translations">Translations</a> of this page</p> |
<blockquote> |
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<p> |
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The free software definition presents the criteria for whether a |
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particular software program qualifies as free software. From time to |
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time we revise this definition, to clarify it or to resolve questions |
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about subtle issues. See the <a href="#History">History section</a> |
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below for a list of changes that affect the definition of free |
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software. |
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</p> |
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<h3>The Free Software Definition</h3> |
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<p> |
<p> |
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<a href="/graphics/philosophicalgnu.html"><img src="/graphics/philosophical-gnu-sm.jpg" alt=" [image of a Philosophical Gnu] " width="160" height="200" /></a> |
“Open source” is something different: it has a very |
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different philosophy based on different values. Its practical |
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definition is different too, but nearly all open source programs are |
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in fact free. We explain the |
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difference <a href="/philosophy/open-source-misses-the-point.html">here</a>. |
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</p> |
</p> |
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</blockquote> |
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<p> |
<p> |
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We maintain this free software definition to show clearly what must be |
“Free software” means software that respects users' |
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true about a particular software program for it to be considered |
freedom and community. Roughly, it means that <b>the users have the |
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free software.</p> |
freedom to run, copy, distribute, study, change and improve the |
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software</b>. Thus, “free software” is a matter of |
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liberty, not price. To understand the concept, you should think of |
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“free” as in “free speech,” not as in |
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“free beer”. We sometimes call it “libre |
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software,” borrowing the French or Spanish word for |
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“free” as in freedom, to show we do not mean the software |
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is gratis. |
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</p> |
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<p> |
<p> |
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``Free software'' is a matter of liberty, not price. To understand the |
We campaign for these freedoms because everyone deserves them. With |
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concept, you should think of ``free'' as in ``free speech,'' not as in |
these freedoms, the users (both individually and collectively) control |
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``free beer.''</p> |
the program and what it does for them. When users don't control the |
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program, we call it a “nonfree” or |
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“proprietary” program. The nonfree program controls the |
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users, and the developer controls the program; this makes the |
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program <a href="/philosophy/free-software-even-more-important.html"> |
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an instrument of unjust power</a>. |
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</p> |
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<h4> The four essential freedoms</h4> |
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<p> |
<p> |
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Free software is a matter of the users' freedom to run, copy, |
A program is free software if the program's users have the |
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distribute, study, change and improve the software. More precisely, |
four essential freedoms: |
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it refers to four kinds of freedom, for the users of the software:</p> |
</p> |
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<ul> |
<ul> |
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<li>The freedom to run the program, for any purpose (freedom 0).</li> |
<li>The freedom to run the program as you wish, |
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<li>The freedom to study how the program works, and adapt it to your needs |
for any purpose (freedom 0).</li> |
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(freedom 1). Access to the source code is a precondition for this.</li> |
<li>The freedom to study how the program works, and change it so it |
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<li>The freedom to redistribute copies so you can help your neighbor |
does your computing as you wish (freedom 1). Access to the source |
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(freedom 2).</li> |
code is a precondition for this. |
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<li>The freedom to improve the program, and release your improvements |
</li> |
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to the public, so that the whole community benefits |
<li>The freedom to redistribute copies so you can help others |
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(freedom 3). Access to the source code is a precondition for this.</li> |
(freedom 2). |
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</li> |
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<li>The freedom to distribute copies of your modified versions |
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to others (freedom 3). By doing this you can give the whole |
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community a chance to benefit from your changes. |
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Access to the source code is a precondition for this. |
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</li> |
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</ul> |
</ul> |
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<p> |
<p> |
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A program is free software if users have all of these freedoms. |
A program is free software if it gives users adequately all of these |
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Thus, you should be free to redistribute copies, either with or |
freedoms. Otherwise, it is nonfree. While we can distinguish various |
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without modifications, either gratis or charging a fee for |
nonfree distribution schemes in terms of how far they fall short of |
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distribution, to <a href="#exportcontrol">anyone anywhere</a>. Being |
being free, we consider them all equally unethical.</p> |
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free to do these things means (among other things) that you do not |
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have to ask or pay for permission.</p> |
<p>In any given scenario, these freedoms must apply to whatever code |
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we plan to make use of, or lead others to make use of. For instance, |
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consider a program A which automatically launches a program B to |
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handle some cases. If we plan to distribute A as it stands, that |
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implies users will need B, so we need to judge whether both A and B |
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are free. However, if we plan to modify A so that it doesn't use B, |
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only A needs to be free; B is not pertinent to that plan.</p> |
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<p> |
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“Free software” does not mean “noncommercial”. A free |
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program must be available for commercial use, commercial development, |
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and commercial distribution. Commercial development of free software |
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is no longer unusual; such free commercial software is very important. |
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You may have paid money to get copies of free software, or you may have |
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obtained copies at no charge. But regardless of how you got your copies, |
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you always have the freedom to copy and change the software, even to |
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<a href="/philosophy/selling.html">sell copies</a>. |
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</p> |
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<p>The rest of this page clarifies certain points about what makes |
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specific freedoms adequate or not.</p> |
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<h4>The freedom to run the program as you wish</h4> |
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<p> |
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The freedom to run the program means the freedom for any kind of person |
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or organization to use it on any kind of computer system, for any kind of |
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overall job and purpose, without being required to communicate about it |
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with the developer or any other specific entity. In this freedom, it is |
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the <em>user's</em> purpose that matters, not the <em>developer's</em> |
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purpose; you as a user are free to run the program for your purposes, |
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and if you distribute it to someone else, she is then free to run it |
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for her purposes, but you are not entitled to impose your purposes on her. |
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</p> |
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<p> |
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The freedom to run the program as you wish means that you are not |
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forbidden or stopped from making it run. This has nothing to do with what |
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functionality the program has, whether it is technically capable of |
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functioning in any given environment, or whether it is useful for any |
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particular computing activity.</p> |
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<h4>The freedom to study the source code and make changes</h4> |
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<p> |
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In order for freedoms 1 and 3 (the freedom to make changes and the |
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freedom to publish the changed versions) to be meaningful, you must have |
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access to the source code of the program. Therefore, accessibility of |
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source code is a necessary condition for free software. Obfuscated |
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“source code” is not real source code and does not count |
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as source code. |
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</p> |
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<p> |
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Freedom 1 includes the freedom to use your changed version in place of |
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the original. If the program is delivered in a product designed to |
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run someone else's modified versions but refuse to run yours — a |
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practice known as “tivoization” or “lockdown”, |
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or (in its practitioners' perverse terminology) as “secure |
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boot” — freedom 1 becomes an empty pretense rather than a |
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practical reality. These binaries are not free |
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software even if the source code they are compiled from is free. |
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</p> |
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<p> |
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One important way to modify a program is by merging in available free |
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subroutines and modules. If the program's license says that you |
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cannot merge in a suitably licensed existing module — for instance, if it |
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requires you to be the copyright holder of any code you add — then the |
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license is too restrictive to qualify as free. |
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</p> |
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<p> |
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Whether a change constitutes an improvement is a subjective matter. |
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If your right to modify a program is limited, in substance, to changes that |
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someone else considers an improvement, that program is not free. |
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</p> |
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<h4>The freedom to redistribute if you wish: basic requirements</h4> |
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<p>Freedom to distribute (freedoms 2 and 3) means you are free to |
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redistribute copies, either with or without modifications, either |
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gratis or charging a fee for distribution, to |
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<a href="#exportcontrol">anyone anywhere</a>. Being free to do these |
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things means (among other things) that you do not have to ask or pay |
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for permission to do so. |
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</p> |
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<p> |
<p> |
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You should also have the freedom to make modifications and use them |
You should also have the freedom to make modifications and use them |
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privately in your own work or play, without even mentioning that they |
privately in your own work or play, without even mentioning that they |
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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 |
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notify anyone in particular, or in any particular way.</p> |
notify anyone in particular, or in any particular way. |
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</p> |
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<p> |
<p> |
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The freedom to use a program means the freedom for any kind of person |
Freedom 3 includes the freedom to release your modified versions |
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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 |
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of overall job, and without being required to communicate subsequently |
releasing them; in other words, it does not have to be |
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with the developer or any other specific entity.</p> |
a <a href="/copyleft/copyleft.html">copyleft</a> license. However, a |
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license that requires modified versions to be nonfree does not qualify |
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as a free license. |
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</p> |
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<p> |
<p> |
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The freedom to redistribute copies must include binary or executable |
The freedom to redistribute copies must include binary or executable |
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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 |
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unmodified versions. (Distributing programs in runnable form is |
unmodified versions. (Distributing programs in runnable form is necessary |
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necessary for conveniently installable free operating systems.) It is |
for conveniently installable free operating systems.) It is OK if there |
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ok if there is no way to produce a binary or executable form for a |
is no way to produce a binary or executable form for a certain program |
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certain program (since some languages don't support that feature), but |
(since some languages don't support that feature), but you must have the |
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you must have the freedom to redistribute such forms should you find |
freedom to redistribute such forms should you find or develop a way to |
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or develop a way to make them.</p> |
make them. |
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<p> |
</p> |
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In order for the freedoms to make changes, and to publish improved |
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versions, to be meaningful, you must have access to the source code of |
<h4>Copyleft</h4> |
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the program. Therefore, accessibility of source code is a necessary |
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condition for free software.</p> |
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<p> |
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In order for these freedoms to be real, they must be irrevocable as |
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long as you do nothing wrong; if the developer of the software has the |
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power to revoke the license, without your doing anything to give |
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cause, the software is not free.</p> |
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<p> |
<p> |
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However, certain kinds of rules about the manner of distributing free |
Certain kinds of rules about the manner of distributing free |
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software are acceptable, when they don't conflict with the central |
software are acceptable, when they don't conflict with the central |
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freedoms. For example, copyleft (very simply stated) is the rule that |
freedoms. For example, <a href="/copyleft/copyleft.html">copyleft</a> |
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when redistributing the program, you cannot add restrictions to deny |
(very simply stated) is the rule that when redistributing the program, |
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other people the central freedoms. This rule does not conflict with |
you cannot add restrictions to deny other people the central freedoms. |
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the central freedoms; rather it protects them.</p> |
This rule does not conflict with the central freedoms; rather it |
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<p> |
protects them. |
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Thus, you may have paid money to get copies of free software, or you |
</p> |
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may have obtained copies at no charge. But regardless of how you got |
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your copies, you always have the freedom to copy and change the |
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software, even to <a href="/philosophy/selling.html">sell copies</a>.</p> |
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<p> |
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``Free software'' does not mean ``non-commercial''. A free program |
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must be available for commercial use, commercial development, and |
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commercial distribution. Commercial development of free software is |
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no longer unusual; such free commercial software is very important.</p> |
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<p> |
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Rules about how to package a modified version are acceptable, if they |
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don't effectively block your freedom to release modified versions. |
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Rules that ``if you make the program available in this way, you must |
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make it available in that way also'' can be acceptable too, on the |
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same condition. (Note that such a rule still leaves you the choice of |
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whether to publish the program or not.) It is also acceptable for the |
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license to require that, if you have distributed a modified version |
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and a previous developer asks for a copy of it, you must send one.</p> |
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<p> |
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In the GNU project, we use <a href="/copyleft/copyleft.html">``copyleft''</a> |
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to protect these freedoms legally for everyone. But |
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<a href="/philosophy/categories.html#Non-CopyleftedFreeSoftware">non-copylefted |
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free software</a> also exists. We believe there are |
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important reasons why <a href="/philosophy/pragmatic.html"> it is |
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better to use copyleft</a>, but if your program is non-copylefted free |
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software, we can still use it.</p> |
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<p> |
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See <a href="/philosophy/categories.html">Categories of Free Software</a> |
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for a description of how ``free software,'' ``copylefted software'' and |
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other categories of software relate to each other.</p> |
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<p> |
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Sometimes government <a id="exportcontrol">export control |
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regulations</a> and trade sanctions can constrain your freedom to |
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distribute copies of programs internationally. Software developers do |
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not have the power to eliminate or override these restrictions, but |
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what they can and must do is refuse to impose them as conditions of |
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use of the program. In this way, the restrictions will not affect |
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activities and people outside the jurisdictions of these governments.</p> |
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<p> |
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Most free software licenses are based on copyright, and there are |
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limits on what kinds of requirements can be imposed through copyright. |
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If a copyright-based license respects freedom in the ways described |
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above, it is unlikely to have some other sort of problem that we never |
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anticipated (though this does happen occasionally). However, some |
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free software licenses are based on contracts, and contracts can |
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impose a much larger range of possible restrictions. That means there |
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are many possible ways such a license could be unacceptably |
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restrictive and non-free.</p> |
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<p> |
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We can't possibly list all the possible contract restrictions that |
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would be unacceptable. If a contract-based license restricts the user |
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in an unusual way that copyright-based licenses cannot, and which |
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isn't mentioned here as legitimate, we will have to think about it, |
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and we will probably decide it is non-free.</p> |
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<p> |
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When talking about free software, it is best to avoid using terms like |
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``give away'' or ``for free'', because those terms imply that the |
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issue is about price, not freedom. Some common terms such as |
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``piracy'' embody opinions we hope you won't endorse. See |
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<a href="/philosophy/words-to-avoid.html">Confusing Words and Phrases |
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that are Worth Avoiding</a> for a discussion of these terms. |
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We also have a list of <a href="/philosophy/fs-translations.html">translations |
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of "free software"</a> into various languages.</p> |
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<p> |
<p> |
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Finally, note that criteria such as those stated in this free software |
In the GNU project, we use copyleft to protect the four freedoms |
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definition require careful thought for their interpretation. To |
legally for everyone. We believe there are important reasons why |
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decide whether a specific software license qualifies as a free |
<a href="/philosophy/pragmatic.html">it is better to use |
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software license, we judge it based on these criteria to determine |
copyleft</a>. However, |
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whether it fits their spirit as well as the precise words. If a |
<a href="/philosophy/categories.html#Non-CopyleftedFreeSoftware"> |
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license includes unconscionable restrictions, we reject it, even if we |
noncopylefted free software</a> is ethical |
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did not anticipate the issue in these criteria. Sometimes a license |
too. See <a href="/philosophy/categories.html">Categories of Free |
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requirement raises an issue that calls for extensive thought, |
Software</a> for a description of how “free software,” |
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including discussions with a lawyer, before we can decide if the |
“copylefted software” and other categories of software |
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requirement is acceptable. When we reach a conclusion about a new |
relate to each other. |
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issue, we often update these criteria to make it easier to see why |
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certain licenses do or don't qualify.</p> |
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<p> |
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If you are interested in whether a specific license qualifies as a |
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free software license, see our <a |
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href="/licenses/license-list.html">list of licenses</a>. If the |
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license you are concerned with is not listed there, you can ask us |
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about it by sending us email at <a |
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href="mailto:licensing@gnu.org"><licensing@gnu.org></a>.</p> <p> |
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If you are contemplating writing a new license, please contact the FSF |
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by writing to that address. The proliferation of different free |
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software licenses means increased work for users in understanding the |
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licenses; we may be able to help you find an existing Free Software |
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license that meets your needs. |
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</p> |
</p> |
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<h4>Rules about packaging and distribution details</h4> |
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<p> |
<p> |
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If that isn't possible, if you really need a new license, with our |
Rules about how to package a modified version are acceptable, |
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help you can ensure that the license really is a Free Software license |
if they don't substantively limit your freedom to release modified |
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and avoid various practical problems. |
versions, or your freedom to make and use modified versions privately. |
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Thus, it is acceptable for the license to require that you change the |
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name of the modified version, remove a logo, or identify your |
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modifications as yours. As long as these requirements are not so |
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burdensome that they effectively hamper you from releasing your |
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changes, they are acceptable; you're already making other changes to |
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the program, so you won't have trouble making a few more. |
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</p> |
</p> |
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<hr /> |
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<p> |
<p> |
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Another group has started using the term "open source" to mean |
Rules that “if you make your version available in this way, you |
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something close (but not identical) to "free software". We prefer the |
must make it available in that way also” can be acceptable too, |
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term "free software" because, once you have heard it refers to freedom |
on the same condition. An example of such an acceptable rule is one |
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rather than price, <a href="free-software-for-freedom.html">it calls |
saying that if you have distributed a |
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to mind freedom</a>.</p> |
modified version and a previous developer asks for a copy of it, you |
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must send one. (Note that such a rule still leaves you the choice of |
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<hr /> |
whether to distribute your version at all.) Rules that require release |
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<h4><a href="/philosophy/philosophy.html">Other Texts to Read</a></h4> |
of source code to the users for versions that you put into public use |
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are also acceptable. |
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<!-- All pages on the GNU web server should have the section about --> |
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<!-- verbatim copying. Please do NOT remove this without talking --> |
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<!-- with the webmasters first. --> |
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<!-- Please make sure the copyright date is consistent with the document --> |
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<!-- and that it is like this "2001, 2002" not this "2001-2002." --> |
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<div class="translations"> |
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<p><a id="translations"></a> |
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<b>Translations of this page</b>:<br /> |
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<!-- Please keep this list alphabetical, and in the original --> |
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<!-- language if possible, otherwise default to English --> |
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<!-- If you do not have it English, please comment what the --> |
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<!-- English is. If you add a new language here, please --> |
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<!-- advise web-trans@gnu.org and add it to --> |
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<!-- - in /home/www/bin/nightly-vars either TAGSLANG or WEBLANG --> |
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<!-- - in /home/www/html/server/standards/README.translations.html --> |
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<!-- one of the lists under the section "Translations Underway" --> |
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<!-- - if there is a translation team, you also have to add an alias --> |
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<!-- to mail.gnu.org:/com/mailer/aliases --> |
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<!-- Please also check you have the 2 letter language code right versus --> |
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<!-- http://www.w3.org/WAI/ER/IG/ert/iso639.htm --> |
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[ |
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<a href="/philosophy/free-sw.cs.html">Česky</a> <!-- Czech --> |
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| <a href="/philosophy/free-sw.da.html">Dansk</a> <!-- Danish --> |
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| <a href="/philosophy/free-sw.de.html">Deutsch</a> <!-- German --> |
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| <a href="/philosophy/free-sw.html">English</a> |
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| <a href="/philosophy/free-sw.es.html">Español</a> <!-- Spanish --> |
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| <a href="/philosophy/free-sw.fr.html">Français</a> <!-- French --> |
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| <a href="/philosophy/free-sw.gl.html">Galego</a> <!-- Galician --> |
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| <a href="/philosophy/free-sw.he.html">עברית</a> <!-- Hebrew --> |
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| <a href="/philosophy/free-sw.hr.html">Hrvatski</a> <!-- Croatian --> |
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| <a href="/philosophy/free-sw.id.html">Bahasa Indonesia</a> <!-- Indonesian --> |
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| <a href="/philosophy/free-sw.it.html">Italiano</a> <!-- Italian --> |
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| <a href="/philosophy/free-sw.ja.html">日本語</a> <!-- Japanese --> |
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| <a href="/philosophy/free-sw.ko.html">한국어</a> <!-- Korean --> |
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| <a href="/philosophy/free-sw.hu.html">Magyar</a> <!-- Hungarian --> |
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| <a href="/philosophy/free-sw.nl.html">Nederlands</a> <!-- Dutch --> |
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| <a href="/philosophy/free-sw.no.html">Norsk</a> <!-- Norwegian --> |
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| <a href="/philosophy/free-sw.pl.html">Polski</a> <!-- Polish --> |
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| <a href="/philosophy/free-sw.pt.html">Português</a> <!-- Portuguese --> |
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| <a href="/philosophy/free-sw.ro.html">Românã</a> <!-- Romanian --> |
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| <a href="/philosophy/free-sw.ru.html">Русский</a> <!-- Russian --> |
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| <a href="/philosophy/free-sw.sl.html">Slovinsko</a> <!--- Slovenian --> |
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| <a href="/philosophy/free-sw.tr.html">Türkçe</a> <!-- Turkish --> |
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] |
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</p> |
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</div> |
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<div class="copyright"> |
|
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<p> |
<p> |
263 |
Return to the <a href="/home.html">GNU Project home page</a>. |
A special issue arises when a license requires changing the name by |
264 |
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which the program will be invoked from other programs. That |
265 |
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effectively hampers you from releasing your changed version so that it |
266 |
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can replace the original when invoked by those other programs. This |
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sort of requirement is acceptable only if there's a suitable aliasing |
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facility that allows you to specify the original program's name as an |
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alias for the modified version.</p> |
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|
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<h4>Export regulations</h4> |
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|
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<p> |
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Sometimes government <a id="exportcontrol">export control regulations</a> |
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and trade sanctions can constrain your freedom to distribute copies of |
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programs internationally. Software developers do not have the power to |
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eliminate or override these restrictions, but what they can and must do |
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is refuse to impose them as conditions of use of the program. In this |
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way, the restrictions will not affect activities and people outside the |
280 |
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jurisdictions of these governments. Thus, free software licenses |
281 |
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must not require obedience to any nontrivial export regulations as a |
282 |
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condition of exercising any of the essential freedoms. |
283 |
</p> |
</p> |
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|
285 |
<p> |
<p> |
286 |
Please send FSF & GNU inquiries to |
Merely mentioning the existence of export regulations, without making |
287 |
<a href="mailto:gnu@gnu.org"><em>gnu@gnu.org</em></a>. |
them a condition of the license itself, is acceptable since it does |
288 |
There are also <a href="/home.html#ContactInfo">other ways to contact</a> |
not restrict users. If an export regulation is actually trivial for |
289 |
the FSF. |
free software, then requiring it as a condition is not an actual |
290 |
<br /> |
problem; however, it is a potential problem, since a later change in |
291 |
Please send broken links and other corrections (or suggestions) to |
export law could make the requirement nontrivial and thus render the |
292 |
<a href="mailto:webmasters@gnu.org"><em>webmasters@gnu.org</em></a>. |
software nonfree. |
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</p> |
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|
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<h4>Legal considerations</h4> |
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|
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<p> |
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In order for these freedoms to be real, they must be permanent and |
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irrevocable as long as you do nothing wrong; if the developer of the |
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software has the power to revoke the license, or retroactively add |
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restrictions to its terms, without your doing anything wrong to give |
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cause, the software is not free. |
303 |
</p> |
</p> |
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|
305 |
<p> |
<p> |
306 |
Please see the |
A free license may not require compliance with the license of a |
307 |
<a href="/server/standards/README.translations.html">Translations |
nonfree program. Thus, for instance, if a license requires you to |
308 |
README</a> for information on coordinating and submitting |
comply with the licenses of “all the programs you use”, in |
309 |
translations of this article. |
the case of a user that runs nonfree programs this would require |
310 |
|
compliance with the licenses of those nonfree programs; that makes the |
311 |
|
license nonfree. |
312 |
</p> |
</p> |
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|
314 |
<p> |
<p> |
315 |
Copyright (C) 1996, 1997, 1998, 1999, 2000, 2001, 2002, 2003, 2004 Free |
It is acceptable for a free license to specify which jurisdiction's |
316 |
Software Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA |
law applies, or where litigation must be done, or both. |
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02111, USA |
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<br /> |
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Verbatim copying and distribution of this entire article is |
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permitted in any medium without royalty provided this notice is |
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preserved. |
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317 |
</p> |
</p> |
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|
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<h4>Contract-based licenses</h4> |
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|
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<p> |
<p> |
322 |
Updated: |
Most free software licenses are based on copyright, and there are limits |
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on what kinds of requirements can be imposed through copyright. If a |
324 |
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copyright-based license respects freedom in the ways described above, it |
325 |
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is unlikely to have some other sort of problem that we never anticipated |
326 |
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(though this does happen occasionally). However, some free software |
327 |
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licenses are based on contracts, and contracts can impose a much larger |
328 |
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range of possible restrictions. That means there are many possible ways |
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such a license could be unacceptably restrictive and nonfree. |
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</p> |
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|
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<p> |
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We can't possibly list all the ways that might happen. If a |
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contract-based license restricts the user in an unusual way that |
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copyright-based licenses cannot, and which isn't mentioned here as |
336 |
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legitimate, we will have to think about it, and we will probably conclude |
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it is nonfree. |
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</p> |
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|
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<h4>Use the right words when talking about free software</h4> |
341 |
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|
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<p> |
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When talking about free software, it is best to avoid using terms |
344 |
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like “give away” or “for free,” because those terms imply that |
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the issue is about price, not freedom. Some common terms such |
346 |
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as “piracy” embody opinions we hope you won't endorse. See |
347 |
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<a href="/philosophy/words-to-avoid.html">Confusing Words and Phrases that |
348 |
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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 |
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“free software”</a> into various languages. |
351 |
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</p> |
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|
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<h4>How we interpret these criteria</h4> |
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|
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<p> |
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Finally, note that criteria such as those stated in this free software |
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definition require careful thought for their interpretation. To decide |
358 |
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whether a specific software license qualifies as a free software license, |
359 |
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we judge it based on these criteria to determine whether it fits their |
360 |
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spirit as well as the precise words. If a license includes unconscionable |
361 |
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restrictions, we reject it, even if we did not anticipate the issue |
362 |
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in these criteria. Sometimes a license requirement raises an issue |
363 |
|
that calls for extensive thought, including discussions with a lawyer, |
364 |
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before we can decide if the requirement is acceptable. When we reach |
365 |
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a conclusion about a new issue, we often update these criteria to make |
366 |
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it easier to see why certain licenses do or don't qualify. |
367 |
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</p> |
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|
369 |
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<h4>Get help with free licenses</h4> |
370 |
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|
371 |
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<p> |
372 |
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If you are interested in whether a specific license qualifies as a free |
373 |
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software license, see our <a href="/licenses/license-list.html">list |
374 |
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of licenses</a>. If the license you are concerned with is not |
375 |
|
listed there, you can ask us about it by sending us email at |
376 |
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<a href="mailto:licensing@gnu.org"><licensing@gnu.org></a>. |
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</p> |
378 |
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|
379 |
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<p> |
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If you are contemplating writing a new license, please contact the |
381 |
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Free Software Foundation first by writing to that address. The |
382 |
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proliferation of different free software licenses means increased work |
383 |
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for users in understanding the licenses; we may be able to help you |
384 |
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find an existing free software license that meets your needs. |
385 |
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</p> |
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|
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<p> |
388 |
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If that isn't possible, if you really need a new license, with our |
389 |
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help you can ensure that the license really is a free software license |
390 |
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and avoid various practical problems. |
391 |
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</p> |
392 |
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|
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<h3 id="beyond-software">Beyond Software</h3> |
394 |
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|
395 |
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<p> |
396 |
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<a href="/philosophy/free-doc.html">Software manuals must be free</a>, |
397 |
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for the same reasons that software must be free, and because the |
398 |
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manuals are in effect part of the software. |
399 |
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</p> |
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|
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<p> |
402 |
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The same arguments also make sense for other kinds of works of |
403 |
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practical use — that is to say, works that embody useful knowledge, |
404 |
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such as educational works and reference |
405 |
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works. <a href="http://wikipedia.org">Wikipedia</a> is the best-known |
406 |
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example. |
407 |
|
</p> |
408 |
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|
409 |
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<p> |
410 |
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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 |
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free cultural works</a> applicable to any kind of works. |
413 |
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</p> |
414 |
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|
415 |
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<h3 id="open-source">Open Source?</h3> |
416 |
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|
417 |
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<p> |
418 |
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Another group uses the term “open source” to mean |
419 |
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something close (but not identical) to “free software”. We |
420 |
|
prefer the term “free software” because, once you have heard that |
421 |
|
it refers to freedom rather than price, it calls to mind freedom. The |
422 |
|
word “open” <a href="/philosophy/open-source-misses-the-point.html"> |
423 |
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never refers to freedom</a>. |
424 |
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</p> |
425 |
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|
426 |
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<h3 id="History">History</h3> |
427 |
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|
428 |
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<p>From time to time we revise this Free Software Definition. Here is |
429 |
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the list of substantive changes, along with links to show exactly what |
430 |
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was changed.</p> |
431 |
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|
432 |
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<ul> |
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|
434 |
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<li><a href="http://web.cvs.savannah.gnu.org/viewvc/www/philosophy/free-sw.html?root=www&r1=1.152&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 |
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|
438 |
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<li><a href="http://web.cvs.savannah.gnu.org/viewvc/www/philosophy/free-sw.html?root=www&r1=1.140&r2=1.141">Version |
439 |
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1.141</a>: Clarify which code needs to be free.</li> |
440 |
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|
441 |
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<li><a href="http://web.cvs.savannah.gnu.org/viewvc/www/philosophy/free-sw.html?root=www&r1=1.134&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 |
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|
445 |
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<li><a href="http://web.cvs.savannah.gnu.org/viewvc/www/philosophy/free-sw.html?root=www&r1=1.133&r2=1.134">Version |
446 |
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1.134</a>: Freedom 0 is not a matter of the program's functionality.</li> |
447 |
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|
448 |
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<li><a href="http://web.cvs.savannah.gnu.org/viewvc/www/philosophy/free-sw.html?root=www&r1=1.130&r2=1.131">Version |
449 |
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1.131</a>: A free license may not require compliance with a nonfree license |
450 |
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of another program.</li> |
451 |
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|
452 |
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<li><a href="http://web.cvs.savannah.gnu.org/viewvc/www/philosophy/free-sw.html?root=www&r1=1.128&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 |
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|
456 |
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<li><a href="http://web.cvs.savannah.gnu.org/viewvc/www/philosophy/free-sw.html?root=www&r1=1.121&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 |
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|
460 |
|
<li><a href="http://web.cvs.savannah.gnu.org/viewvc/www/philosophy/free-sw.html?root=www&r1=1.117&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 “improvements”</li> |
464 |
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|
465 |
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<li><a href="http://web.cvs.savannah.gnu.org/viewvc/www/philosophy/free-sw.html?root=www&r1=1.110&r2=1.111">Version |
466 |
|
1.111</a>: Clarify 1.77 by saying that only |
467 |
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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&r1=1.104&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 |
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|
476 |
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<li><a href="http://web.cvs.savannah.gnu.org/viewvc/www/philosophy/free-sw.html?root=www&r1=1.91&r2=1.92">Version |
477 |
|
1.92</a>: Clarify that obfuscated code does not qualify as source code.</li> |
478 |
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|
479 |
|
<li><a href="http://web.cvs.savannah.gnu.org/viewvc/www/philosophy/free-sw.html?root=www&r1=1.89&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&r1=1.88&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&r1=1.79&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&r1=1.76&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&r1=1.73&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&r1=1.56&r2=1.57">Version |
512 |
|
1.57</a>: Add "Beyond Software" section.</li> |
513 |
|
|
514 |
|
<li><a href="http://web.cvs.savannah.gnu.org/viewvc/www/philosophy/free-sw.html?root=www&r1=1.45&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&r1=1.40&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&r1=1.39&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&r1=1.38&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&r1=1.30&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&r1=1.22&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&r1=1.15&r2=1.16">Version |
540 |
|
1.16</a>: Explain why distribution of binaries is important.</li> |
541 |
|
|
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