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Preamble
The licenses for most software are designed to take away your freedom to share and change it. By con-
trast, the GNU General Public License is intended to guarantee your freedom to share and change free
software--to make sure the software is free for all its users. This General Public License applies to most
of the Free Software Foundation‘s software and to any other program whose authors commit to using it.
(Some other Free Software Foundation software is covered by the GNU Library General Public License
instead.) 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
this service 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 make restrictions that forbid anyone to deny you these rights or to ask
you to surrender the rights. These restrictions translate to certain responsibilities for you if you distribute
copies of the software, or if you modify it. For example, if you distribute copies of such a program,
whether gratis or for a fee, you must give the recipients all the rights that you have. 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.
We protect your rights with two steps:
(1) copyright the software, and (2) offer you this license which gives you legal permission to copy, distri-
bute and/or modify the software. Also, for each author‘s protection and ours, we want to make certain
that everyone understands that there is no warranty for this free software.
If the software is modified by someone else and passed on, we want its recipients to know that what they
have is not the original, so that any problems introduced by others will not reflect on the original authors‘
reputations.
Finally, any free program is threatened constantly by software patents.
We wish to avoid the danger that redistributors of a free program will individually obtain patent licenses,
in effect making the program proprietary. To prevent this, we have made it clear that any patent must be
licensed for everyone‘s free use or not licensed at all.
The precise terms and conditions for copying, distribution and modification follow.
TERMS AND CONDITIONS FOR COPYING, DISTRIBUTION AND MODIFICATION
This License applies to any program or other work which contains a notice placed by the copyright
holder saying it may be distributed under the terms of this General Public License. The “Program”, below,
refers to any such program or work, and a “work based on the Program” means either the Program or
any derivative work under copyright law: that is to say, a work containing the Program or a portion of it,
either verbatim or with modifications and/or translated into another language. (Hereinafter, translation is
included without limitation in the term “modification”.) Each licensee is addressed as “you”.
Activities other than copying, distribution and modification are not covered by this License; they are
outside its scope. The act of running the Program is not restricted, and the output from the Program is
covered only if its contents constitute a work based on the Program (independent of having been made
by running the Program). Whether that is true depends on what the Program does.
You may copy and distribute verbatim copies of the Program’s source code as you receive it, in any
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