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<title>What is free software? |
<title>What is free software? |
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- GNU Project - Free Software Foundation</title> |
- GNU Project - Free Software Foundation</title> |
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<h2>What is free software?</h2> |
<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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<h3>The Free Software Definition</h3> |
<h3>The Free Software Definition</h3> |
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<blockquote> |
<blockquote> |
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<p> |
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“Free software” means software that respects users' |
“Free software” means software that respects users' |
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freedom and community. Roughly, <b>the users have the freedom to run, |
freedom and community. Roughly, it means that <b>the users have the |
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copy, distribute, study, change and improve the software</b>. |
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> |
</p> |
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<p> |
<p> |
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Thus, “free software” is a matter of liberty, not price. |
We campaign for these freedoms because everyone deserves them. With |
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To understand the concept, you should think of “free” as |
these freedoms, the users (both individually and collectively) control |
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in “free speech,” not as in “free beer”. |
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> |
</p> |
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<p> |
<h4> The four essential freedoms</h4> |
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With these freedoms, the users (both individually and collectively) |
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control the program and what it does for them. When users don't |
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control the program, the program controls the users. The developer |
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controls the program, and through it exercises power over the users. |
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Therefore, a “nonfree” or “proprietary” program |
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is <a href="/philosophy/free-software-even-more-important.html"> an |
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instrument of unjust power</a>. |
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</p> |
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<p> |
<p> |
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A program is free software if the program's users have the |
A program is free software if the program's users have the |
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</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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for any purpose (freedom 0).</li> |
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<li>The freedom to study how the program works, and change it so it |
<li>The freedom to study how the program works, and change it so it |
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does your computing as you wish (freedom 1). Access to the source |
does your computing as you wish (freedom 1). Access to the source |
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code is a precondition for this. |
code is a precondition for this. |
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nonfree distribution schemes in terms of how far they fall short of |
nonfree distribution schemes in terms of how far they fall short of |
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being free, we consider them all equally unethical.</p> |
being free, we consider them all equally unethical.</p> |
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<p>The rest of this page clarifies certain points about what makes |
<p>In any given scenario, these freedoms must apply to whatever code |
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specific freedoms adequate or not.</p> |
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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<p>Freedom to distribute (freedoms 2 and 3) means you are free to |
handle some cases. If we plan to distribute A as it stands, that |
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redistribute copies, either with or without modifications, either |
implies users will need B, so we need to judge whether both A and B |
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gratis or charging a fee for distribution, to |
are free. However, if we plan to modify A so that it doesn't use B, |
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<a href="#exportcontrol">anyone anywhere</a>. Being free to do these |
only A needs to be free; B is not pertinent to that plan.</p> |
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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 |
“Free software” does not mean “noncommercial”. A free |
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privately in your own work or play, without even mentioning that they |
program must be available for commercial use, commercial development, |
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exist. If you do publish your changes, you should not be required to |
and commercial distribution. Commercial development of free software |
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notify anyone in particular, or in any particular way. |
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> |
</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> |
<p> |
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The freedom to run the program means the freedom for any kind of person |
The freedom to run the program means the freedom for any kind of person |
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or organization to use it on any kind of computer system, for any kind of |
or organization to use it on any kind of computer system, for any kind of |
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</p> |
</p> |
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<p> |
<p> |
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The freedom to redistribute copies must include binary or executable |
The freedom to run the program as you wish means that you are not |
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forms of the program, as well as source code, for both modified and |
forbidden or stopped from making it run. This has nothing to do with what |
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unmodified versions. (Distributing programs in runnable form is necessary |
functionality the program has, whether it is technically capable of |
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for conveniently installable free operating systems.) It is OK if there |
functioning in any given environment, or whether it is useful for any |
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is no way to produce a binary or executable form for a certain program |
particular computing activity.</p> |
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(since some languages don't support that feature), but you must have the |
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freedom to redistribute such forms should you find or develop a way to |
<h4>The freedom to study the source code and make changes</h4> |
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make them. |
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</p> |
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<p> |
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In order for freedoms 1 and 3 (the freedom to make changes and the |
In order for freedoms 1 and 3 (the freedom to make changes and the |
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run someone else's modified versions but refuse to run yours — a |
run someone else's modified versions but refuse to run yours — a |
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practice known as “tivoization” or “lockdown”, |
practice known as “tivoization” or “lockdown”, |
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or (in its practitioners' perverse terminology) as “secure |
or (in its practitioners' perverse terminology) as “secure |
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boot” — freedom 1 becomes a theoretical fiction rather |
boot” — freedom 1 becomes an empty pretense rather than a |
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than a practical freedom. This is not sufficient. In other words, |
practical reality. These binaries are not free |
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these binaries are not free software even if the source code they are |
software even if the source code they are compiled from is free. |
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compiled from is free. |
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</p> |
</p> |
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<p> |
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</p> |
</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> |
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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 |
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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. |
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</p> |
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Freedom 3 includes the freedom to release your modified versions |
Freedom 3 includes the freedom to release your modified versions |
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as free software. A free license may also permit other ways of |
as free software. A free license may also permit other ways of |
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releasing them; in other words, it does not have to be |
releasing them; in other words, it does not have to be |
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</p> |
</p> |
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<p> |
<p> |
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In order for these freedoms to be real, they must be permanent and |
The freedom to redistribute copies must include binary or executable |
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irrevocable as long as you do nothing wrong; if the developer of the |
forms of the program, as well as source code, for both modified and |
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software has the power to revoke the license, or retroactively add |
unmodified versions. (Distributing programs in runnable form is necessary |
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restrictions to its terms, without your doing anything wrong to give |
for conveniently installable free operating systems.) It is OK if there |
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cause, the software is not free. |
is no way to produce a binary or executable form for a certain program |
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(since some languages don't support that feature), but you must have the |
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freedom to redistribute such forms should you find or develop a way to |
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make them. |
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</p> |
</p> |
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<h4>Copyleft</h4> |
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<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. |
This rule does not conflict with the central freedoms; rather it |
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protects them. |
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</p> |
</p> |
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<p> |
<p> |
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“Free software” does not mean “noncommercial”. A free |
In the GNU project, we use copyleft to protect the four freedoms |
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program must be available for commercial use, commercial development, |
legally for everyone. We believe there are important reasons why |
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and commercial distribution. Commercial development of free software |
<a href="/philosophy/pragmatic.html">it is better to use |
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is no longer unusual; such free commercial software is very important. |
copyleft</a>. However, |
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You may have paid money to get copies of free software, or you may have |
<a href="/philosophy/categories.html#Non-CopyleftedFreeSoftware"> |
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obtained copies at no charge. But regardless of how you got your copies, |
noncopylefted free software</a> is ethical |
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you always have the freedom to copy and change the software, even to |
too. See <a href="/philosophy/categories.html">Categories of Free |
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<a href="/philosophy/selling.html">sell copies</a>. |
Software</a> for a description of how “free software,” |
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“copylefted software” and other categories of software |
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relate to each other. |
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</p> |
</p> |
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<p> |
<h4>Rules about packaging and distribution details</h4> |
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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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<p> |
<p> |
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However, rules about how to package a modified version are acceptable, |
Rules about how to package a modified version are acceptable, |
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if they don't substantively limit your freedom to release modified |
if they don't substantively limit your freedom to release modified |
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versions, or your freedom to make and use modified versions privately. |
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 |
Thus, it is acceptable for the license to require that you change the |
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facility that allows you to specify the original program's name as an |
facility that allows you to specify the original program's name as an |
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alias for the modified version.</p> |
alias for the modified version.</p> |
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<p> |
<h4>Export regulations</h4> |
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In the GNU project, we use |
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<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">noncopylefted |
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free software</a> also exists. We believe there are important reasons why |
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<a href="/philosophy/pragmatic.html">it is better to use copyleft</a>, |
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but if your program is noncopylefted free software, it is still basically |
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ethical. (See <a href="/philosophy/categories.html">Categories of Free Software</a> for a description of how “free software,” “copylefted software” and other categories of software relate to each other.) |
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</p> |
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<p> |
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Sometimes government <a id="exportcontrol">export control regulations</a> |
Sometimes government <a id="exportcontrol">export control regulations</a> |
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software nonfree. |
software nonfree. |
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</p> |
</p> |
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<h4>Legal considerations</h4> |
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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. |
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</p> |
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<p> |
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A free license may not require compliance with the license of a |
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nonfree program. Thus, for instance, if a license requires you to |
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comply with the licenses of “all the programs you use”, in |
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the case of a user that runs nonfree programs this would require |
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compliance with the licenses of those nonfree programs; that makes the |
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license nonfree. |
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</p> |
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<p> |
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It is acceptable for a free license to specify which jurisdiction's |
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law applies, or where litigation must be done, or both. |
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</p> |
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<h4>Contract-based licenses</h4> |
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<p> |
<p> |
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Most free software licenses are based on copyright, and there are limits |
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 |
on what kinds of requirements can be imposed through copyright. If a |
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it is nonfree. |
it is nonfree. |
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</p> |
</p> |
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<h4>Use the right words when talking about free software</h4> |
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<p> |
<p> |
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When talking about free software, it is best to avoid using terms |
When talking about free software, it is best to avoid using terms |
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like “give away” or “for free,” because those terms imply that |
like “give away” or “for free,” because those terms imply that |
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“free software”</a> into various languages. |
“free software”</a> into various languages. |
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</p> |
</p> |
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<h4>How we interpret these criteria</h4> |
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<p> |
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Finally, note that criteria such as those stated in this free software |
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 |
definition require careful thought for their interpretation. To decide |
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it easier to see why certain licenses do or don't qualify. |
it easier to see why certain licenses do or don't qualify. |
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</p> |
</p> |
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<h4>Get help with free licenses</h4> |
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<p> |
<p> |
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If you are interested in whether a specific license qualifies as a free |
If you are interested in whether a specific license qualifies as a free |
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software license, see our <a href="/licenses/license-list.html">list |
software license, see our <a href="/licenses/license-list.html">list |
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<h3 id="open-source">Open Source?</h3> |
<h3 id="open-source">Open Source?</h3> |
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<p> |
<p> |
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Another group has started using the term “open source” to mean |
Another group uses the term “open source” to mean |
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something close (but not identical) to “free software”. We |
something close (but not identical) to “free software”. We |
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prefer the term “free software” because, once you have heard that |
prefer the term “free software” because, once you have heard that |
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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 |
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<ul> |
<ul> |
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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 |
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1.153</a>: Clarify that freedom to run the program means nothing stops |
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you from making it run.</li> |
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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 |
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1.141</a>: Clarify which code needs to be free.</li> |
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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 |
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1.135</a>: Say each time that freedom 0 is the freedom to run the program |
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as you wish.</li> |
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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 |
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1.134</a>: Freedom 0 is not a matter of the program's functionality.</li> |
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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 |
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1.131</a>: A free license may not require compliance with a nonfree license |
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of another program.</li> |
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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 |
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1.129</a>: State explicitly that choice of law and choice of forum |
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specifications are allowed. (This was always our policy.)</li> |
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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 |
<li><a href="http://web.cvs.savannah.gnu.org/viewvc/www/philosophy/free-sw.html?root=www&r1=1.121&r2=1.122">Version |
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1.122</a>: An export control requirement is a real problem if the |
1.122</a>: An export control requirement is a real problem if the |
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requirement is nontrivial; otherwise it is only a potential problem.</li> |
requirement is nontrivial; otherwise it is only a potential problem.</li> |
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<li><a href="http://web.cvs.savannah.gnu.org/viewvc/www/philosophy/free-sw.html?root=www&r1=1.10&r2=1.11">Version |
<li><a href="http://web.cvs.savannah.gnu.org/viewvc/www/philosophy/free-sw.html?root=www&r1=1.10&r2=1.11">Version |
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1.11</a>: Note that a free license may require you to send a copy of |
1.11</a>: Note that a free license may require you to send a copy of |
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versions you distribute to the author.</li> |
versions you distribute to previous developers on request.</li> |
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</ul> |
</ul> |
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<div id="footer"> |
<div id="footer"> |
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<div class="unprintable"> |
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<p>Please send general FSF & GNU inquiries to |
<p>Please send general FSF & GNU inquiries to |
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<a href="mailto:gnu@gnu.org"><gnu@gnu.org></a>. |
<a href="mailto:gnu@gnu.org"><gnu@gnu.org></a>. |
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href="/server/standards/README.translations.html">Translations |
href="/server/standards/README.translations.html">Translations |
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README</a> for information on coordinating and submitting translations |
README</a> for information on coordinating and submitting translations |
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of this article.</p> |
of this article.</p> |
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files generated as part of manuals) on the GNU web server should |
files generated as part of manuals) on the GNU web server should |
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be under CC BY-ND 3.0 US. Please do NOT change or remove this |
be under CC BY-ND 4.0. Please do NOT change or remove this |
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without talking with the webmasters or licensing team first. |
without talking with the webmasters or licensing team first. |
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Please make sure the copyright date is consistent with the |
Please make sure the copyright date is consistent with the |
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document. For web pages, it is ok to list just the latest year the |
document. For web pages, it is ok to list just the latest year the |
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There is more detail about copyright years in the GNU Maintainers |
There is more detail about copyright years in the GNU Maintainers |
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Information document, www.gnu.org/prep/maintain. --> |
Information document, www.gnu.org/prep/maintain. --> |
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<p>Copyright © 1996-2002, 2004-2007, 2009, 2010, 2012, 2013 |
<p>Copyright © 1996, 2002, 2004-2007, 2009-2016 |
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Free Software Foundation, Inc.</p> |
Free Software Foundation, Inc.</p> |
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<p>This page is licensed under a <a rel="license" |
<p>This page is licensed under a <a rel="license" |
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href="http://creativecommons.org/licenses/by-nd/3.0/us/">Creative |
href="http://creativecommons.org/licenses/by-nd/4.0/">Creative |
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Commons Attribution-NoDerivs 3.0 United States License</a>.</p> |
Commons Attribution-NoDerivatives 4.0 International License</a>.</p> |
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<p>Updated: |
<p class="unprintable">Updated: |
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