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<title>What is free software? |
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- GNU Project - Free Software Foundation</title> |
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<title>The Free Software Definition - GNU Project - Free Software Foundation (FSF)</title> |
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<meta http-equiv="Keywords" content="GNU, FSF, Free Software Foundation, Linux, Emacs, GCC, Unix, Free Software, Operating System, GNU Kernel, HURD, GNU HURD, Hurd" /> |
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<meta http-equiv="Description" content="Since 1983, developing the free Unix style operating system GNU, so that computer users can have the freedom to share and improve the software they use." /> |
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<p><a href="#translations">Translations</a> of this page</p> |
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<h2>What is free software?</h2> |
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<h3>The Free Software Definition</h3> |
<h3>The Free Software Definition</h3> |
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<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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</blockquote> |
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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> |
“Free software” means software that respects users' |
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freedom and community. Roughly, <b>the users have the freedom to run, |
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copy, distribute, study, change and improve the software</b>. |
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</p> |
</p> |
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<p> |
<p> |
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We maintain this free software definition to show clearly what must be |
Thus, “free software” is a matter of liberty, not price. |
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true about a particular software program for it to be considered |
To understand the concept, you should think of “free” as |
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free software.</p> |
in “free speech,” not as in “free beer”. |
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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 |
With these freedoms, the users (both individually and collectively) |
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concept, you should think of ``free'' as in ``free speech,'' not as in |
control the program and what it does for them. When users don't |
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``free beer.''</p> |
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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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, for any purpose (freedom 0).</li> |
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<li>The freedom to study how the program works, and adapt it to your needs |
<li>The freedom to study how the program works, and change it so it |
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(freedom 1). Access to the source code is a precondition for this.</li> |
does your computing as you wish (freedom 1). Access to the source |
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code is a precondition for this. |
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</li> |
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<li>The freedom to redistribute copies so you can help your neighbor |
<li>The freedom to redistribute copies so you can help your neighbor |
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(freedom 2).</li> |
(freedom 2). |
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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 distribute copies of your modified versions |
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(freedom 3). Access to the source code is a precondition for this.</li> |
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>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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<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 |
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 |
or organization to use it on any kind of computer system, for any kind of |
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of overall job, and without being required to communicate subsequently |
overall job and purpose, without being required to communicate about it |
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with the developer or any other specific entity.</p> |
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> |
<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 |
<p> |
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the program. Therefore, accessibility of source code is a necessary |
In order for freedoms 1 and 3 (the freedom to make changes and the |
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condition for free software.</p> |
freedom to publish the changed versions) to be meaningful, you must have |
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<p> |
access to the source code of the program. Therefore, accessibility of |
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In order for these freedoms to be real, they must be irrevocable as |
source code is a necessary condition for free software. Obfuscated |
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long as you do nothing wrong; if the developer of the software has the |
“source code” is not real source code and does not count |
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power to revoke the license, without your doing anything to give |
as source code. |
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cause, the software is not free.</p> |
</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 a theoretical fiction rather |
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than a practical freedom. This is not sufficient. In other words, |
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these binaries are not free software even if the source code they are |
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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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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 |
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releasing them; in other words, it does not have to be |
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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> |
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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> |
<p> |
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However, certain kinds of rules about the manner of distributing free |
However, 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, copyleft (very simply stated) is the rule that |
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when redistributing the program, you cannot add restrictions to deny |
when redistributing the program, you cannot add restrictions to deny |
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other people the central freedoms. This rule does not conflict with |
other people the central freedoms. This rule does not conflict with |
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the central freedoms; rather it protects them.</p> |
the central freedoms; rather it protects them. |
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</p> |
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<p> |
<p> |
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You may have paid money to get copies of free software, or you |
“Free software” does not mean “noncommercial”. A free |
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may have obtained copies at no charge. But regardless of how you got |
program must be available for commercial use, commercial development, |
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your copies, you always have the freedom to copy and change the |
and commercial distribution. Commercial development of free software |
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software, even to <a href="/philosophy/selling.html">sell copies</a>.</p> |
is no longer unusual; such free commercial software is very important. |
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<p> |
You may have paid money to get copies of free software, or you may have |
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``Free software'' does not mean ``non-commercial''. A free program |
obtained copies at no charge. But regardless of how you got your copies, |
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must be available for commercial use, commercial development, and |
you always have the freedom to copy and change the software, even to |
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commercial distribution. Commercial development of free software is |
<a href="/philosophy/selling.html">sell copies</a>. |
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no longer unusual; such free commercial software is very important.</p> |
</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 substantively 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, |
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or that you identify yourself on your modifications.</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 |
Whether a change constitutes an improvement is a subjective matter. |
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definition require careful thought for their interpretation. To |
If your right to modify a program is limited, in substance, to changes that |
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decide whether a specific software license qualifies as a free |
someone else considers an improvement, that program is not free. |
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software license, we judge it based on these criteria to determine |
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whether it fits their spirit as well as the precise words. If a |
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license includes unconscionable restrictions, we reject it, even if we |
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did not anticipate the issue in these criteria. Sometimes a license |
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requirement raises an issue that calls for extensive thought, |
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including discussions with a lawyer, before we can decide if the |
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requirement is acceptable. When we reach a conclusion about a new |
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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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<p> |
<p> |
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If that isn't possible, if you really need a new license, with our |
However, 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>. The word "open" never does that.</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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<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.ca.html">Català</a> <!-- Catalan --> |
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<!-- Chinese (Simplified) --> |
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| <a href="/philosophy/free-sw.cn.html">简体中文</a> |
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<!-- Chinese (Traditional) --> |
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| <a href="/philosophy/free-sw.zh.html">繁體中文</a> |
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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 --> |
|
|
| <a href="/philosophy/free-sw.de.html">Deutsch</a> <!-- German --> |
|
|
| <a href="/philosophy/free-sw.html">English</a> |
|
|
| <a href="/philosophy/free-sw.es.html">Español</a> <!-- Spanish --> |
|
|
|
|
|
<!-- Persian/Farsi --> |
|
|
| <a href="/philosophy/free-sw.fa.html">فارسی</a> |
|
|
|
|
|
| <a href="/philosophy/free-sw.fr.html">Français</a> <!-- French --> |
|
|
| <a href="/philosophy/free-sw.gl.html">Galego</a> <!-- Galician --> |
|
|
| <a href="/philosophy/free-sw.he.html">עברית</a> <!-- Hebrew --> |
|
|
| <a href="/philosophy/free-sw.hr.html">Hrvatski</a> <!-- Croatian --> |
|
|
| <a href="/philosophy/free-sw.id.html">Bahasa Indonesia</a> <!-- Indonesian --> |
|
|
| <a href="/philosophy/free-sw.it.html">Italiano</a> <!-- Italian --> |
|
|
| <a href="/philosophy/free-sw.ja.html">日本語</a> <!-- Japanese --> |
|
|
| <a href="/philosophy/free-sw.ko.html">한국어</a> <!-- Korean --> |
|
|
| <a href="/philosophy/free-sw.hu.html">Magyar</a> <!-- Hungarian --> |
|
|
| <a href="/philosophy/free-sw.nl.html">Nederlands</a> <!-- Dutch --> |
|
|
| <a href="/philosophy/free-sw.no.html">Norsk</a> <!-- Norwegian --> |
|
|
| <a href="/philosophy/free-sw.pl.html">Polski</a> <!-- Polish --> |
|
|
| <a href="/philosophy/free-sw.pt.html">Português</a> <!-- Portuguese --> |
|
|
| <a href="/philosophy/free-sw.ro.html">Română</a> <!-- Romanian --> |
|
|
| <a href="/philosophy/free-sw.ru.html">Русский</a> <!-- Russian --> |
|
|
| <a href="/philosophy/free-sw.sl.html">Slovinsko</a> <!--- Slovenian --> |
|
|
| <a href="/philosophy/free-sw.sr.html">Српски</a> <!-- Serbian --> |
|
|
| <a href="/philosophy/free-sw.tr.html">Türkçe</a> <!-- Turkish --> |
|
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] |
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</p> |
</p> |
|
</div> |
|
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|
<div class="copyright"> |
|
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<p> |
<p> |
| 213 |
Return to the <a href="/home.html">GNU Project home page</a>. |
A special issue arises when a license requires changing the name by |
| 214 |
|
which the program will be invoked from other programs. That |
| 215 |
|
effectively hampers you from releasing your changed version so that it |
| 216 |
|
can replace the original when invoked by those other programs. This |
| 217 |
|
sort of requirement is acceptable only if there's a suitable aliasing |
| 218 |
|
facility that allows you to specify the original program's name as an |
| 219 |
|
alias for the modified version.</p> |
| 220 |
|
|
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|
<p> |
| 222 |
|
In the GNU project, we use |
| 223 |
|
<a href="/copyleft/copyleft.html">copyleft</a> |
| 224 |
|
to protect these freedoms legally for everyone. But |
| 225 |
|
<a href="/philosophy/categories.html#Non-CopyleftedFreeSoftware">noncopylefted |
| 226 |
|
free software</a> also exists. We believe there are important reasons why |
| 227 |
|
<a href="/philosophy/pragmatic.html">it is better to use copyleft</a>, |
| 228 |
|
but if your program is noncopylefted free software, it is still basically |
| 229 |
|
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.) |
| 230 |
</p> |
</p> |
| 231 |
|
|
| 232 |
<p> |
<p> |
| 233 |
Please send FSF & GNU inquiries to |
Sometimes government <a id="exportcontrol">export control regulations</a> |
| 234 |
<a href="mailto:gnu@gnu.org"><em>gnu@gnu.org</em></a>. |
and trade sanctions can constrain your freedom to distribute copies of |
| 235 |
There are also <a href="/home.html#ContactInfo">other ways to contact</a> |
programs internationally. Software developers do not have the power to |
| 236 |
the FSF. |
eliminate or override these restrictions, but what they can and must do |
| 237 |
<br /> |
is refuse to impose them as conditions of use of the program. In this |
| 238 |
Please send broken links and other corrections (or suggestions) to |
way, the restrictions will not affect activities and people outside the |
| 239 |
<a href="mailto:webmasters@gnu.org"><em>webmasters@gnu.org</em></a>. |
jurisdictions of these governments. Thus, free software licenses |
| 240 |
|
must not require obedience to any nontrivial export regulations as a |
| 241 |
|
condition of exercising any of the essential freedoms. |
| 242 |
</p> |
</p> |
| 243 |
|
|
| 244 |
<p> |
<p> |
| 245 |
Please see the |
Merely mentioning the existence of export regulations, without making |
| 246 |
<a href="/server/standards/README.translations.html">Translations |
them a condition of the license itself, is acceptable since it does |
| 247 |
README</a> for information on coordinating and submitting |
not restrict users. If an export regulation is actually trivial for |
| 248 |
translations of this article. |
free software, then requiring it as a condition is not an actual |
| 249 |
|
problem; however, it is a potential problem, since a later change in |
| 250 |
|
export law could make the requirement nontrivial and thus render the |
| 251 |
|
software nonfree. |
| 252 |
</p> |
</p> |
| 253 |
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|
| 254 |
<p> |
<p> |
| 255 |
Copyright (C) 1996, 1997, 1998, 1999, 2000, 2001, 2002, 2003, 2004 Free |
Most free software licenses are based on copyright, and there are limits |
| 256 |
Software Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA |
on what kinds of requirements can be imposed through copyright. If a |
| 257 |
02111, USA |
copyright-based license respects freedom in the ways described above, it |
| 258 |
<br /> |
is unlikely to have some other sort of problem that we never anticipated |
| 259 |
Verbatim copying and distribution of this entire article is |
(though this does happen occasionally). However, some free software |
| 260 |
permitted in any medium without royalty provided this notice is |
licenses are based on contracts, and contracts can impose a much larger |
| 261 |
preserved. |
range of possible restrictions. That means there are many possible ways |
| 262 |
|
such a license could be unacceptably restrictive and nonfree. |
| 263 |
</p> |
</p> |
| 264 |
|
|
| 265 |
<p> |
<p> |
| 266 |
Updated: |
We can't possibly list all the ways that might happen. If a |
| 267 |
|
contract-based license restricts the user in an unusual way that |
| 268 |
|
copyright-based licenses cannot, and which isn't mentioned here as |
| 269 |
|
legitimate, we will have to think about it, and we will probably conclude |
| 270 |
|
it is nonfree. |
| 271 |
|
</p> |
| 272 |
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|
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<p> |
| 274 |
|
When talking about free software, it is best to avoid using terms |
| 275 |
|
like “give away” or “for free,” because those terms imply that |
| 276 |
|
the issue is about price, not freedom. Some common terms such |
| 277 |
|
as “piracy” embody opinions we hope you won't endorse. See |
| 278 |
|
<a href="/philosophy/words-to-avoid.html">Confusing Words and Phrases that |
| 279 |
|
are Worth Avoiding</a> for a discussion of these terms. We also have |
| 280 |
|
a list of proper <a href="/philosophy/fs-translations.html">translations of |
| 281 |
|
“free software”</a> into various languages. |
| 282 |
|
</p> |
| 283 |
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|
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<p> |
| 285 |
|
Finally, note that criteria such as those stated in this free software |
| 286 |
|
definition require careful thought for their interpretation. To decide |
| 287 |
|
whether a specific software license qualifies as a free software license, |
| 288 |
|
we judge it based on these criteria to determine whether it fits their |
| 289 |
|
spirit as well as the precise words. If a license includes unconscionable |
| 290 |
|
restrictions, we reject it, even if we did not anticipate the issue |
| 291 |
|
in these criteria. Sometimes a license requirement raises an issue |
| 292 |
|
that calls for extensive thought, including discussions with a lawyer, |
| 293 |
|
before we can decide if the requirement is acceptable. When we reach |
| 294 |
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a conclusion about a new issue, we often update these criteria to make |
| 295 |
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it easier to see why certain licenses do or don't qualify. |
| 296 |
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</p> |
| 297 |
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|
| 298 |
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<p> |
| 299 |
|
If you are interested in whether a specific license qualifies as a free |
| 300 |
|
software license, see our <a href="/licenses/license-list.html">list |
| 301 |
|
of licenses</a>. If the license you are concerned with is not |
| 302 |
|
listed there, you can ask us about it by sending us email at |
| 303 |
|
<a href="mailto:licensing@gnu.org"><licensing@gnu.org></a>. |
| 304 |
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</p> |
| 305 |
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|
| 306 |
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<p> |
| 307 |
|
If you are contemplating writing a new license, please contact the |
| 308 |
|
Free Software Foundation first by writing to that address. The |
| 309 |
|
proliferation of different free software licenses means increased work |
| 310 |
|
for users in understanding the licenses; we may be able to help you |
| 311 |
|
find an existing free software license that meets your needs. |
| 312 |
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</p> |
| 313 |
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|
| 314 |
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<p> |
| 315 |
|
If that isn't possible, if you really need a new license, with our |
| 316 |
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help you can ensure that the license really is a free software license |
| 317 |
|
and avoid various practical problems. |
| 318 |
|
</p> |
| 319 |
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|
| 320 |
|
<h3 id="beyond-software">Beyond Software</h3> |
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| 322 |
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<p> |
| 323 |
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<a href="/philosophy/free-doc.html">Software manuals must be free</a>, |
| 324 |
|
for the same reasons that software must be free, and because the |
| 325 |
|
manuals are in effect part of the software. |
| 326 |
|
</p> |
| 327 |
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|
| 328 |
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<p> |
| 329 |
|
The same arguments also make sense for other kinds of works of |
| 330 |
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practical use — that is to say, works that embody useful knowledge, |
| 331 |
|
such as educational works and reference |
| 332 |
|
works. <a href="http://wikipedia.org">Wikipedia</a> is the best-known |
| 333 |
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example. |
| 334 |
|
</p> |
| 335 |
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|
| 336 |
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<p> |
| 337 |
|
Any kind of work <em>can</em> be free, and the definition of free software |
| 338 |
|
has been extended to a definition of <a href="http://freedomdefined.org/"> |
| 339 |
|
free cultural works</a> applicable to any kind of works. |
| 340 |
|
</p> |
| 341 |
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|
| 342 |
|
<h3 id="open-source">Open Source?</h3> |
| 343 |
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|
| 344 |
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<p> |
| 345 |
|
Another group has started using the term “open source” to mean |
| 346 |
|
something close (but not identical) to “free software”. We |
| 347 |
|
prefer the term “free software” because, once you have heard that |
| 348 |
|
it refers to freedom rather than price, it calls to mind freedom. The |
| 349 |
|
word “open” <a href="/philosophy/open-source-misses-the-point.html"> |
| 350 |
|
never refers to freedom</a>. |
| 351 |
|
</p> |
| 352 |
|
|
| 353 |
|
<h3 id="History">History</h3> |
| 354 |
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|
| 355 |
|
<p>From time to time we revise this Free Software Definition. Here is |
| 356 |
|
the list of substantive changes, along with links to show exactly what |
| 357 |
|
was changed.</p> |
| 358 |
|
|
| 359 |
|
<ul> |
| 360 |
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|
| 361 |
|
<li><a href="http://web.cvs.savannah.gnu.org/viewvc/www/philosophy/free-sw.html?root=www&r1=1.121&r2=1.122">Version |
| 362 |
|
1.122</a>: An export control requirement is a real problem if the |
| 363 |
|
requirement is nontrivial; otherwise it is only a potential problem.</li> |
| 364 |
|
|
| 365 |
|
<li><a href="http://web.cvs.savannah.gnu.org/viewvc/www/philosophy/free-sw.html?root=www&r1=1.117&r2=1.118">Version |
| 366 |
|
1.118</a>: Clarification: the issue is limits on your right to modify, |
| 367 |
|
not on what modifications you have made. And modifications are not limited |
| 368 |
|
to “improvements”</li> |
| 369 |
|
|
| 370 |
|
<li><a href="http://web.cvs.savannah.gnu.org/viewvc/www/philosophy/free-sw.html?root=www&r1=1.110&r2=1.111">Version |
| 371 |
|
1.111</a>: Clarify 1.77 by saying that only |
| 372 |
|
retroactive <em>restrictions</em> are unacceptable. The copyright |
| 373 |
|
holders can always grant additional <em>permission</em> for use of the |
| 374 |
|
work by releasing the work in another way in parallel.</li> |
| 375 |
|
|
| 376 |
|
<li><a href="http://web.cvs.savannah.gnu.org/viewvc/www/philosophy/free-sw.html?root=www&r1=1.104&r2=1.105">Version |
| 377 |
|
1.105</a>: Reflect, in the brief statement of freedom 1, the point |
| 378 |
|
(already stated in version 1.80) that it includes really using your modified |
| 379 |
|
version for your computing.</li> |
| 380 |
|
|
| 381 |
|
<li><a href="http://web.cvs.savannah.gnu.org/viewvc/www/philosophy/free-sw.html?root=www&r1=1.91&r2=1.92">Version |
| 382 |
|
1.92</a>: Clarify that obfuscated code does not qualify as source code.</li> |
| 383 |
|
|
| 384 |
|
<li><a href="http://web.cvs.savannah.gnu.org/viewvc/www/philosophy/free-sw.html?root=www&r1=1.89&r2=1.90">Version |
| 385 |
|
1.90</a>: Clarify that freedom 3 means the right to distribute copies |
| 386 |
|
of your own modified or improved version, not a right to participate |
| 387 |
|
in someone else's development project.</li> |
| 388 |
|
|
| 389 |
|
<li><a href="http://web.cvs.savannah.gnu.org/viewvc/www/philosophy/free-sw.html?root=www&r1=1.88&r2=1.89">Version |
| 390 |
|
1.89</a>: Freedom 3 includes the right to release modified versions as |
| 391 |
|
free software.</li> |
| 392 |
|
|
| 393 |
|
<li><a href="http://web.cvs.savannah.gnu.org/viewvc/www/philosophy/free-sw.html?root=www&r1=1.79&r2=1.80">Version |
| 394 |
|
1.80</a>: Freedom 1 must be practical, not just theoretical; |
| 395 |
|
i.e., no tivoization.</li> |
| 396 |
|
|
| 397 |
|
<li><a href="http://web.cvs.savannah.gnu.org/viewvc/www/philosophy/free-sw.html?root=www&r1=1.76&r2=1.77">Version |
| 398 |
|
1.77</a>: Clarify that all retroactive changes to the license are |
| 399 |
|
unacceptable, even if it's not described as a complete |
| 400 |
|
replacement.</li> |
| 401 |
|
|
| 402 |
|
<li><a href="http://web.cvs.savannah.gnu.org/viewvc/www/philosophy/free-sw.html?root=www&r1=1.73&r2=1.74">Version |
| 403 |
|
1.74</a>: Four clarifications of points not explicit enough, or stated |
| 404 |
|
in some places but not reflected everywhere: |
| 405 |
|
<ul> |
| 406 |
|
<li>"Improvements" does not mean the license can |
| 407 |
|
substantively limit what kinds of modified versions you can release. |
| 408 |
|
Freedom 3 includes distributing modified versions, not just changes.</li> |
| 409 |
|
<li>The right to merge in existing modules |
| 410 |
|
refers to those that are suitably licensed.</li> |
| 411 |
|
<li>Explicitly state the conclusion of the point about export controls.</li> |
| 412 |
|
<li>Imposing a license change constitutes revoking the old license.</li> |
| 413 |
|
</ul> |
| 414 |
|
</li> |
| 415 |
|
|
| 416 |
|
<li><a href="http://web.cvs.savannah.gnu.org/viewvc/www/philosophy/free-sw.html?root=www&r1=1.56&r2=1.57">Version |
| 417 |
|
1.57</a>: Add "Beyond Software" section.</li> |
| 418 |
|
|
| 419 |
|
<li><a href="http://web.cvs.savannah.gnu.org/viewvc/www/philosophy/free-sw.html?root=www&r1=1.45&r2=1.46">Version |
| 420 |
|
1.46</a>: Clarify whose purpose is significant in the freedom to run |
| 421 |
|
the program for any purpose.</li> |
| 422 |
|
|
| 423 |
|
<li><a href="http://web.cvs.savannah.gnu.org/viewvc/www/philosophy/free-sw.html?root=www&r1=1.40&r2=1.41">Version |
| 424 |
|
1.41</a>: Clarify wording about contract-based licenses.</li> |
| 425 |
|
|
| 426 |
|
<li><a href="http://web.cvs.savannah.gnu.org/viewvc/www/philosophy/free-sw.html?root=www&r1=1.39&r2=1.40">Version |
| 427 |
|
1.40</a>: Explain that a free license must allow to you use other |
| 428 |
|
available free software to create your modifications.</li> |
| 429 |
|
|
| 430 |
|
<li><a href="http://web.cvs.savannah.gnu.org/viewvc/www/philosophy/free-sw.html?root=www&r1=1.38&r2=1.39">Version |
| 431 |
|
1.39</a>: Note that it is acceptable for a license to require you to |
| 432 |
|
provide source for versions of the software you put into public |
| 433 |
|
use.</li> |
| 434 |
|
|
| 435 |
|
<li><a href="http://web.cvs.savannah.gnu.org/viewvc/www/philosophy/free-sw.html?root=www&r1=1.30&r2=1.31">Version |
| 436 |
|
1.31</a>: Note that it is acceptable for a license to require you to |
| 437 |
|
identify yourself as the author of modifications. Other minor |
| 438 |
|
clarifications throughout the text.</li> |
| 439 |
|
|
| 440 |
|
<li><a href="http://web.cvs.savannah.gnu.org/viewvc/www/philosophy/free-sw.html?root=www&r1=1.22&r2=1.23">Version |
| 441 |
|
1.23</a>: Address potential problems related to contract-based |
| 442 |
|
licenses.</li> |
| 443 |
|
|
| 444 |
|
<li><a href="http://web.cvs.savannah.gnu.org/viewvc/www/philosophy/free-sw.html?root=www&r1=1.15&r2=1.16">Version |
| 445 |
|
1.16</a>: Explain why distribution of binaries is important.</li> |
| 446 |
|
|
| 447 |
|
<li><a href="http://web.cvs.savannah.gnu.org/viewvc/www/philosophy/free-sw.html?root=www&r1=1.10&r2=1.11">Version |
| 448 |
|
1.11</a>: Note that a free license may require you to send a copy of |
| 449 |
|
versions you distribute to the author.</li> |
| 450 |
|
|
| 451 |
|
</ul> |
| 452 |
|
|
| 453 |
|
<p>There are gaps in the version numbers shown above because there are |
| 454 |
|
other changes in this page that do not affect the definition or its |
| 455 |
|
interpretations. For instance, the list does not include changes in |
| 456 |
|
asides, formatting, spelling, punctuation, or other parts of the page. |
| 457 |
|
You can review the complete list of changes to the page through |
| 458 |
|
the <a href="http://web.cvs.savannah.gnu.org/viewvc/www/philosophy/free-sw.html?root=www&view=log">cvsweb |
| 459 |
|
interface</a>.</p> |
| 460 |
|
|
| 461 |
|
|
| 462 |
|
</div><!-- for id="content", starts in the include above --> |
| 463 |
|
<!--#include virtual="/server/footer.html" --> |
| 464 |
|
<div id="footer"> |
| 465 |
|
|
| 466 |
|
<p>Please send general FSF & GNU inquiries to |
| 467 |
|
<a href="mailto:gnu@gnu.org"><gnu@gnu.org></a>. |
| 468 |
|
There are also <a href="/contact/">other ways to contact</a> |
| 469 |
|
the FSF. Broken links and other corrections or suggestions can be sent |
| 470 |
|
to <a href="mailto:webmasters@gnu.org"><webmasters@gnu.org></a>.</p> |
| 471 |
|
|
| 472 |
|
<p><!-- TRANSLATORS: Ignore the original text in this paragraph, |
| 473 |
|
replace it with the translation of these two: |
| 474 |
|
|
| 475 |
|
We work hard and do our best to provide accurate, good quality |
| 476 |
|
translations. However, we are not exempt from imperfection. |
| 477 |
|
Please send your comments and general suggestions in this regard |
| 478 |
|
to <a href="mailto:web-translators@gnu.org"> |
| 479 |
|
<web-translators@gnu.org></a>.</p> |
| 480 |
|
|
| 481 |
|
<p>For information on coordinating and submitting translations of |
| 482 |
|
our web pages, see <a |
| 483 |
|
href="/server/standards/README.translations.html">Translations |
| 484 |
|
README</a>. --> |
| 485 |
|
Please see the <a |
| 486 |
|
href="/server/standards/README.translations.html">Translations |
| 487 |
|
README</a> for information on coordinating and submitting translations |
| 488 |
|
of this article.</p> |
| 489 |
|
|
| 490 |
|
<!-- Regarding copyright, in general, standalone pages (as opposed to |
| 491 |
|
files generated as part of manuals) on the GNU web server should |
| 492 |
|
be under CC BY-ND 3.0 US. Please do NOT change or remove this |
| 493 |
|
without talking with the webmasters or licensing team first. |
| 494 |
|
Please make sure the copyright date is consistent with the |
| 495 |
|
document. For web pages, it is ok to list just the latest year the |
| 496 |
|
document was modified, or published. |
| 497 |
|
|
| 498 |
|
If you wish to list earlier years, that is ok too. |
| 499 |
|
Either "2001, 2002, 2003" or "2001-2003" are ok for specifying |
| 500 |
|
years, as long as each year in the range is in fact a copyrightable |
| 501 |
|
year, i.e., a year in which the document was published (including |
| 502 |
|
being publicly visible on the web or in a revision control system). |
| 503 |
|
|
| 504 |
|
There is more detail about copyright years in the GNU Maintainers |
| 505 |
|
Information document, www.gnu.org/prep/maintain. --> |
| 506 |
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<p>Copyright © 1996-2002, 2004-2007, 2009, 2010, 2012, 2013 |
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