GNU General Public Licence
Version 2, June 1991
Copyright (C) 1989,
1991 Free Software Foundation, Inc.
51 Franklin Street, Fifth Floor, Boston,
MA 02110-1301, USA
Everyone is permitted to copy and distribute verbatim copies of
this license document, but changing it is not allowed.
Preamble
The licenses for most software are designed to take away your
freedom to share and change it. By contrast, 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 Lesser General Pu-
blic 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 soft-
ware (and charge for this service if you wish), that you recei-
ve 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, whe-
ther gratis or for a fee, you must give the recipients all the
rights that you have. You must make sure that they, too, recei-
ve 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 soft-
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