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, distribute 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 modifi ed 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 refl ect 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 modifi cation follow.
TERMS AND CONDITIONS FOR COPYING, DISTRIBUTION AND MODIFICATION
0. 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 modifi cations and/or translated
into another language. (Hereinafter, translation is included without limitation in the term “modifi cation”.) Each licensee
is addressed as “you”.
Activities other than copying, distribution and modifi cation 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.
1. You may copy and distribute verbatim copies of the Program’s source code as you receive it, in any medium, provided
that you conspicuously and appropriately publish on each copy an appropriate copyright notice and disclaimer of
warranty; keep intact all the notices that refer to this License and to the absence of any warranty; and give any other
recipients of the Program a copy of this License along with the Program.
You may charge a fee for the physical act of transferring a copy, and you may at your option offer warranty protection
in exchange for a fee.
2. You may modify your copy or copies of the Program or any portion of it, thus forming a work based on the Program,
and copy and distribute such modifi cations or work under the terms of Section 1 above, provided that you also meet
all of these conditions:
a) You must cause the modifi ed fi les to carry prominent notices stating that you changed the fi les and the date of any
change.
b) You must cause any work that you distribute or publish, that in whole or in part contains or is derived from the
Program or any part thereof, to be licensed as a whole at no charge to all third parties under the terms of this
License.
c) If the modifi ed program normally reads commands interactively when run, you must cause it, when started running
for such interactive use in the most ordinary way, to print or display an announcement including an appropriate
copyright notice and a notice that there is no warranty (or else, saying that you provide a warranty) and that users
may redistribute the program under these conditions, and telling the user how to view a copy of this License.
(Exception: if the Program itself is interactive but does not normally print such an announcement, your work based
on the Program is not required to print an announcement.)
These requirements apply to the modifi ed work as a whole. If identifi able sections of that work are not derived from
the Program, and can be reasonably considered independent and separate works in themselves, then this License,
and its terms, do not apply to those sections when you distribute them as separate works. But when you distribute the
same sections as part of a whole which is a work based on the Program, the distribution of the whole must be on the
terms of this License, whose permissions for other licensees extend to the entire whole, and thus to each and every
part regardless of who wrote it.
Thus, it is not the intent of this section to claim rights or contest your rights to work written entirely by you; rather, the
intent is to exercise the right to control the distribution of derivative or collective works based on the Program.
In addition, mere aggregation of another work not based on the Program with the Program (or with a work based on
the Program) on a volume of a storage or distribution medium does not bring the other work under the scope of this
License.
