Developers that use the GNU GPL protect your rights with two
steps: (1) assert copyright on the software, and (2) offer you this
License giving you legal permission to copy, distribute and/or
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Finally, every program is threatened constantly by software
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and use of software on general-purpose computers, but in those
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to a free program could make it effectively proprietary. To
prevent this, the GPL assures that patents cannot be used to
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The precise terms and conditions for copying, distribution and
modification follow.
TERMS AND CONDITIONS
0. Definitions. “This License” refers to version 3 of the GNU
General Public License. “Copyright” also means copyright-like
laws that apply to other kinds of works, such as semiconductor
masks. “The Program” refers to any copyrightable work licensed
under this License. Each licensee is addressed as “you”.
“Licensees” and “recipients” may be individuals or organizations.
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A “covered work” means either the unmodified Program or a
work based on the Program.
To “propagate” a work means to do anything with it that,
without permission, would make you directly or secondarily
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Propagation includes copying, distribution (with or without
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An interactive user interface displays “Appropriate Legal
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prominently visible feature that (1) displays an appropriate
copyright notice, and (2) tells the user that there is no warranty
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1. Source Code.
The “source code” for a work means the preferred form of the
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the work, or an object code interpreter used to run it.
The “Corresponding Source” for a work in object code form
means all the source code needed to generate, install, and (for
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does not include the work's System Libraries, or general-
purpose tools or generally available free programs which are
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between those subprograms and other parts of the work.
The Corresponding Source need not include anything that users
can regenerate automatically from other parts of the
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The Corresponding Source for a work in source code form is
that same work.
2. Basic Permissions.
All rights granted under this License are granted for the term of
copyright on the Program, and are irrevocable provided the
stated conditions are met. This License explicitly affirms your
unlimited permission to run the unmodified Program. The
output from running a covered work is covered by this License
only if the output, given its content, constitutes a covered work.
This License acknowledges your rights of fair use or other
equivalent, as provided by copyright law.
You may make, run and propagate covered works that you do
not convey, without conditions so long as your license otherwise
remains in force. You may convey covered works to others for
the sole purpose of having them make modifications exclusively
for you, or provide you with facilities for running those works,
provided that you comply with the terms of this License in
conveying all material for which you do not control copyright.
Those thus making or running the covered works for you must
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control, on terms that prohibit them from making any copies of
your copyrighted material outside their relationship with you.
Conveying under any other circumstances is permitted solely
under the conditions stated below. Sublicensing is not allowed;
section 10 makes it unnecessary.
3. Protecting Users' Legal Rights From Anti-Circumvention Law.
No covered work shall be deemed part of an effective
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