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.
c) If the modified 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 modified work
as a whole. If identifiable 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.
3. You may copy and distribute the Program
(or a work based on it, under Section 2) in
object code or executable form under the terms
of Sections 1 and 2 above provided that you
also do one of the following:
a) Accompany it with the complete corresponding
machine-readable source code, which must be
distributed under the terms of Sections 1 and
2 above on a medium customarily used for software
interchange; or,
b) Accompany it with a written offer, valid
for at least three years, to give any third
party, for a charge no more than your cost of
physically performing source distribution, a
complete machine-readable copy of the corresponding
source code, to be distributed under the terms
of Sections 1 and 2 above on a medium customarily
used for software interchange; or,
c) Accompany it with the information you received
as to the offer to distribute corresponding
source code. (This alternative is allowed only
for noncommercial distribution and only if you
received the program in object code or executable
form with such an offer, in accord with Subsection
b above.)
The source code for a work means the preferred
form of the work for making modifications to
it. For an executable work, complete source
code means all the source code for all modules
it contains, plus any associated interface definition
files, plus the scripts used to control compilation
and installation of the executable. However,
as a special exception, the source code distributed
need not include anything that is normally distributed
(in either source or binary form) with the major
components (compiler, kernel, and so on) of
the operating system on which the executable
runs, unless that component itself accompanies
the executable.
If distribution of executable or object code
is made by offering access to copy from a designated
place, then offering equivalent access to copy
the source code from the same place counts as
distribution of the source code, even though
third parties are not compelled to copy the
source along with the object code.
4. You may not copy, modify, sublicense, or
distribute the Program except as expressly provided
under this License. Any attempt otherwise to
copy, modify, sublicense or distribute the Program
is void, and will automatically terminate your
rights under this License. However, parties
who have received copies, or rights, from you
under this License will not have their licenses
terminated so long as such parties remain in
full compliance.
5. You are not required to accept this License,
since you have not signed it. However, nothing
else grants you permission to modify or distribute
the Program or its derivative works. These actions
are prohibited by law if you do not accept this
License. Therefore, by modifying or distributing
the Program (or any work based on the Program),
you indicate your acceptance of this License
to do so, and all its terms and conditions for
copying, distributing or modifying the Program
or works based on it.
6. Each time you redistribute the Program (or
any work based on the Program), the recipient
automatically receives a license from the original
licensor to copy, distribute or modify the Program
subject to these terms and conditions. You may
not impose any further restrictions on the recipients'
exercise of the rights granted herein. You are
not responsible for enforcing compliance by
third parties to this License.
7. If, as a consequence of a court judgment
or allegation of patent infringement or for
any other reason (not limited to patent issues),
conditions are imposed on you (whether by court
order, agreement or otherwise) that contradict
the conditions of this License, they do not
excuse you from the conditions of this License.
If you cannot distribute so as to satisfy simultaneously
your obligations under this License and any
other pertinent obligations, then as a consequence
you may not distribute the Program at all. For
example, if a patent license would not permit
royalty-free redistribution of the Program by
all those who receive copies directly or indirectly
through you, then the only way you could satisfy
both it and this License would be to refrain
entirely from distribution of the Program.
If any portion of this section is held invalid
or unenforceable under any particular circumstance,
the balance of the section is intended to apply
and the section as a whole is intended to apply
in other circumstances.
It is not the purpose of this section to induce
you to infringe any patents or other property
right claims or to contest validity of any such
claims; this section has the sole purpose of
protecting the integrity of the free software
distribution system, which is implemented by
public license practices. Many people have made
generous contributions to the wide range of
software distributed through that system in
reliance on consistent application of that system;
it is up to the author/donor to decide if he
or she is willing to distribute software through
any other system and a licensee cannot impose
that choice.
This section is intended to make thoroughly
clear what is believed to be a consequence of
the rest of this License.
8. If the distribution and/or use of the Program
is restricted in certain countries either by
patents or by copyrighted interfaces, the original
copyright holder who places the Program under
this License may add an explicit geographical
distribution limitation excluding those countries,
so that distribution is permitted only in or
among countries not thus excluded. In such case,
this License incorporates the limitation as
if written in the body of this License.
9. The Free Software Foundation may publish
revised and/or new versions of the General Public
License from time to time. Such new versions
will be similar in spirit to the present version,
but may differ in detail to address new problems
or concerns.
Each version is given a distinguishing version
number. If the Program specifies a version number
of this License which applies to it and "any
later version", you have the option of
following the terms and conditions either of
that version or of any later version published
by the Free Software Foundation. If the Program
does not specify a version number of this License,
you may choose any version ever published by
the Free Software Foundation.
10. If you wish to incorporate parts of the
Program into other free programs whose distribution
conditions are different, write to the author
to ask for permission. For software which is
copyrighted by the Free Software Foundation,
write to the Free Software Foundation; we sometimes
make exceptions for this. Our decision will
be guided by the two goals of preserving the
free status of all derivatives of our free software
and of promoting the sharing and reuse of software
generally.
NO WARRANTY
11. BECAUSE THE PROGRAM IS LICENSED FREE OF
CHARGE, THERE IS NO WARRANTY FOR THE PROGRAM,
TO THE EXTENT PERMITTED BY APPLICABLE LAW. EXCEPT
WHEN OTHERWISE STATED IN WRITING THE COPYRIGHT
HOLDERS AND/OR OTHER PARTIES PROVIDE THE PROGRAM
"AS IS" WITHOUT WARRANTY OF ANY KIND,
EITHER EXPRESSED OR IMPLIED, INCLUDING, BUT
NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY
AND FITNESS FOR A PARTICULAR PURPOSE. THE ENTIRE
RISK AS TO THE QUALITY AND PERFORMANCE OF THE
PROGRAM IS WITH YOU. SHOULD THE PROGRAM PROVE
DEFECTIVE, YOU ASSUME THE COST OF ALL NECESSARY
SERVICING, REPAIR OR CORRECTION.
12. IN NO EVENT UNLESS REQUIRED BY APPLICABLE
LAW OR AGREED TO IN WRITING WILL ANY COPYRIGHT
HOLDER, OR ANY OTHER PARTY WHO MAY MODIFY AND/OR
REDISTRIBUTE THE PROGRAM AS PERMITTED ABOVE,
BE LIABLE TO YOU FOR DAMAGES, INCLUDING ANY
GENERAL, SPECIAL, INCIDENTAL OR CONSEQUENTIAL
DAMAGES ARISING OUT OF THE USE OR INABILITY
TO USE THE PROGRAM (INCLUDING BUT NOT LIMITED
TO LOSS OF DATA OR DATA BEING RENDERED INACCURATE
OR LOSSES SUSTAINED BY YOU OR THIRD PARTIES
OR A FAILURE OF THE PROGRAM TO OPERATE WITH
ANY OTHER PROGRAMS), EVEN IF SUCH HOLDER OR
OTHER PARTY HAS BEEN ADVISED OF THE POSSIBILITY
OF SUCH DAMAGES.