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Version 3, 29 June 2007
Copyright © 2007 Free Software Foundation, Inc. <http://fsf.org/>
Everyone is permitted to copy and distribute verbatim copies of this
license document, but changing it is not allowed.
Preamble
The GNU General Public License is a free, copyleft license for software
and other kinds of works.
The licenses for most s oftware and other practical works are designed
to take away your freedom to share and change the works. By
contrast, the GNU General Public License is intended to guarantee
your freedom to share and change all versions of a program--to make
sure it remains free software for all its users. We, the Free Software
Foundation, use the GNU General Public License for most of our
software; it applies also to any other work released this way by its
authors. You can apply it to your programs, too.
When we speak of free software, we are referring to freedom, not
price. Our General Public Licenses are designed to make sure that you
have the freedom to distribute copies of free software (and charge
for them if you wish), that you receive source code or can get it if you
want it, that you can change the software or use pieces of it in new
free programs, and that you know you can do these things.
To protect your rights, we need to prevent others from denying you
these rights or asking you to surrender the rights. Therefore, you have
certain responsibilities if you distribute copies of the software, or if you
modify it: responsibilities to respect the freedom of others.
For example, if you distribute copies of such a program, whether gratis
or for a fee, you must pass on to the recipients the same freedoms that
you received. You must make sure that they, too, receive or can get
the source code. And you must show them these terms so they know
their rights.
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
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