The GNU General Public License (GPL)

Version 2, June 1991

Copyright (C) 1989, 1991 Free Software Foundation, Inc.

59 Temple Place, Suite 330, Boston, MA 02111-1307 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 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, 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 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

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 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.

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 modifications

or work under the terms of Section 1 above, provided that you also meet all of

these conditions:

    a) You must cause the modified files to carry prominent notices stating

    that you changed the files 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.