LICENSE.txt

Home GNU General Public License, version 3 (GPL-3.0)

GNU GENERAL PUBLIC LICENSE Version 3, 29 June 2007

Copyright (C) 2007 Free Software Foundation, Inc. <http://fsf.org/>

Everyone is permitted to copy and distribute verbatim copies of this
license document, but changing it is not allowed.

Preamble The GNU General Public License is a free, copyleft license for
software and other kinds of works.

The licenses for most software and other practical works are designed to
take away your freedom to share and change the works. By contrast, the GNU
General Public License is intended to guarantee your freedom to share and
change all versions of a program--to make sure it remains free software for
all its users. We, the Free Software Foundation, use the GNU General Public
License for most of our software; it applies also to any other work
released this way by its authors. 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 them 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 prevent others from denying you these
rights or asking you to surrender the rights. Therefore, you have certain
responsibilities if you distribute copies of the software, or if you modify
it: responsibilities to respect the freedom of others.

For example, if you distribute copies of such a program, whether gratis or
for a fee, you must pass on to the recipients the same freedoms that you
received. 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.

Developers that use the GNU GPL protect your rights with two steps: (1)
assert copyright on the software, and (2) offer you this License giving you
legal permission to copy, distribute and/or modify it.

For the developers' and authors' protection, the GPL clearly explains that
there is no warranty for this free software. For both users' and authors'
sake, the GPL requires that modified versions be marked as changed, so that
their problems will not be attributed erroneously to authors of previous
versions.

Some devices are designed to deny users access to install or run modified
versions of the software inside them, although the manufacturer can do so.
This is fundamentally incompatible with the aim of protecting users'
freedom to change the software. The systematic pattern of such abuse occurs
in the area of products for individuals to use, which is precisely where it
is most unacceptable. Therefore, we have designed this version of the GPL
to prohibit the practice for those products. If such problems arise
substantially in other domains, we stand ready to extend this provision to
those domains in future versions of the GPL, as needed to protect the
freedom of users.

Finally, every program is threatened constantly by software patents. States
should not allow patents to restrict development and use of software on
general-purpose computers, but in those that do, we wish to avoid the
special danger that patents applied to a free program could make it
effectively proprietary. To prevent this, the GPL assures that patents
cannot be used to render the program non-free.

The precise terms and conditions for copying, distribution and modification
follow.

TERMS AND CONDITIONS

0. Definitions. “This License” refers to version 3 of the GNU General
Public License.

“Copyright” also means copyright-like laws that apply to other kinds of
works, such as semiconductor masks.

“The Program” refers to any copyrightable work licensed under this License.
Each licensee is addressed as “you”. “Licensees” and “recipients” may be
individuals or organizations.

To “modify” a work means to copy from or adapt all or part of the work in a
fashion requiring copyright permission, other than the making of an exact
copy. The resulting work is called a “modified version” of the earlier work
or a work “based on” the earlier work.

A “covered work” means either the unmodified Program or a work based on the
Program.

To “propagate” a work means to do anything with it that, without
permission, would make you directly or secondarily liable for infringement
under applicable copyright law, except executing it on a computer or
modifying a private copy. Propagation includes copying, distribution (with
or without modification), making available to the public, and in some
countries other activities as well.

To “convey” a work means any kind of propagation that enables other parties
to make or receive copies. Mere interaction with a user through a computer
network, with no transfer of a copy, is not conveying.

An interactive user interface displays “Appropriate Legal Notices” to the
extent that it includes a convenient and prominently visible feature that
(1) displays an appropriate copyright notice, and (2) tells the user that
there is no warranty for the work (except to the extent that warranties are
provided), that licensees may convey the work under this License, and how
to view a copy of this License. If the interface presents a list of user
commands or options, such as a menu, a prominent item in the list meets
this criterion.

1. Source Code. The “source code” for a work means the preferred form of
the work for making modifications to it. “Object code” means any non-source
form of a work.

A “Standard Interface” means an interface that either is an official
standard defined by a recognized standards body, or, in the case of
interfaces specified for a particular programming language, one that is
widely used among developers working in that language.

The “System Libraries” of an executable work include anything, other than
the work as a whole, that (a) is included in the normal form of packaging a
Major Component, but which is not part of that Major Component, and (b)
serves only to enable use of the work with that Major Component, or to
implement a Standard Interface for which an implementation is available to
the public in source code form. A “Major Component”, in this context, means
a major essential component (kernel, window system, and so on) of the
specific operating system (if any) on which the executable work runs, or a
compiler used to produce the work, or an object code interpreter used to
run it.

The “Corresponding Source” for a work in object code form means all the
source code needed to generate, install, and (for an executable work) run
the object code and to modify the work, including scripts to control those
activities. However, it does not include the work's System Libraries, or
general-purpose tools or generally available free programs which are used
unmodified in performing those activities but which are not part of the
work. For example, Corresponding Source includes interface definition files
associated with source files for the work, and the source code for shared
libraries and dynamically linked subprograms that the work is specifically
designed to require, such as by intimate data communication or control flow
between those subprograms and other parts of the work.

The Corresponding Source need not include anything that users can
regenerate automatically from other parts of the Corresponding Source.

The Corresponding Source for a work in source code form is that same work.

2. Basic Permissions. All rights granted under this License are granted for
the term of copyright on the Program, and are irrevocable provided the
stated conditions are met. This License explicitly affirms your unlimited
permission to run the unmodified Program. The output from running a covered
work is covered by this License only if the output, given its content,
constitutes a covered work. This License acknowledges your rights of fair
use or other equivalent, as provided by copyright law.

You may make, run and propagate covered works that you do not convey,
without conditions so long as your license otherwise remains in force. You
may convey covered works to others for the sole purpose of having them make
modifications exclusively for you, or provide you with facilities for
running those works, provided that you comply with the terms of this
License in conveying all material for which you do not control copyright.
Those thus making or running the covered works for you must do so
exclusively on your behalf, under your direction and control, on terms that
prohibit them from making any copies of your copyrighted material outside
their relationship with you.

Conveying under any other circumstances is permitted solely under the
conditions stated below. Sublicensing is not allowed; section 10 makes it
unnecessary.

3. Protecting Users' Legal Rights From Anti-Circumvention Law. No covered
work shall be deemed part of an effective technological measure under any
applicable law fulfilling obligations under article 11 of the WIPO
copyright treaty adopted on 20 December 1996, or similar laws prohibiting
or restricting circumvention of such measures.

When you convey a covered work, you waive any legal power to forbid
circumvention of technological measures to the extent such circumvention is
effected by exercising rights under this License with respect to the
covered work, and you disclaim any intention to limit operation or
modification of the work as a means of enforcing, against the work's users,
your or third parties' legal rights to forbid circumvention of
technological measures.

4. Conveying Verbatim Copies. You may convey 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; keep intact all notices stating that this License and any
non-permissive terms added in accord with section 7 apply to the code; keep
intact all notices of the absence of any warranty; and give all recipients
a copy of this License along with the Program.

You may charge any price or no price for each copy that you convey, and you
may offer support or warranty protection for a fee.

5. Conveying Modified Source Versions. You may convey a work based on the
Program, or the modifications to produce it from the Program, in the form
of source code under the terms of section 4, provided that you also meet
all of these conditions:

a) The work must carry prominent notices stating that you modified it, and
giving a relevant date. b) The work must carry prominent notices stating
that it is released under this License and any conditions added under
section 7. This requirement modifies the requirement in section 4 to “keep
intact all notices”. c) You must license the entire work, as a whole, under
this License to anyone who comes into possession of a copy. This License
will therefore apply, along with any applicable section 7 additional terms,
to the whole of the work, and all its parts, regardless of how they are
packaged. This License gives no permission to license the work in any other
way, but it does not invalidate such permission if you have separately
received it. d) If the work has interactive user interfaces, each must
display Appropriate Legal Notices; however, if the Program has interactive
interfaces that do not display Appropriate Legal Notices, your work need
not make them do so. A compilation of a covered work with other separate
and independent works, which are not by their nature extensions of the
covered work, and which are not combined with it such as to form a larger
program, in or on a volume of a storage or distribution medium, is called
an “aggregate” if the compilation and its resulting copyright are not used
to limit the access or legal rights of the compilation's users beyond what
the individual works permit. Inclusion of a covered work in an aggregate
does not cause this License to apply to the other parts of the aggregate.

6. Conveying Non-Source Forms. You may convey a covered work in object code
form under the terms of sections 4 and 5, provided that you also convey the
machine-readable Corresponding Source under the terms of this License, in
one of these ways:

a) Convey the object code in, or embodied in, a physical product (including
a physical distribution medium), accompanied by the Corresponding Source
fixed on a durable physical medium customarily used for software
interchange. b) Convey the object code in, or embodied in, a physical
product (including a physical distribution medium), accompanied by a
written offer, valid for at least three years and valid for as long as you
offer spare parts or customer support for that product model, to give
anyone who possesses the object code either (1) a copy of the Corresponding
Source for all the software in the product that is covered by this License,
on a durable physical medium customarily used for software interchange, for
a price no more than your reasonable cost of physically performing this
conveying of source, or (2) access to copy the Corresponding Source from a
network server at no charge. c) Convey individual copies of the object code
with a copy of the written offer to provide the Corresponding Source. This
alternative is allowed only occasionally and noncommercially, and only if
you received the object code with such an offer, in accord with subsection
6b. d) Convey the object code by offering access from a designated place
(gratis or for a charge), and offer equivalent access to the Corresponding
Source in the same way through the same place at no further charge. You
need not require recipients to copy the Corresponding Source along with the
object code. If the place to copy the object code is a network server, the
Corresponding Source may be on a different server (operated by you or a
third party) that supports equivalent copying facilities, provided you
maintain clear directions next to the object code saying where to find the
Corresponding Source. Regardless of what server hosts the Corresponding
Source, you remain obligated to ensure that it is available for as long as
needed to satisfy these requirements. e) Convey the object code using
peer-to-peer transmission, provided you inform other peers where the object
code and Corresponding Source of the work are being offered to the general
public at no charge under subsection 6d. A separable portion of the object
code, whose source code is excluded from the Corresponding Source as a
System Library, need not be included in conveying the object code work.

A “User Product” is either (1) a “consumer product”, which means any
tangible personal property which is normally used for personal, family, or
household purposes, or (2) anything designed or sold for incorporation into
a dwelling. In determining whether a product is a consumer product,
doubtful cases shall be resolved in favor of coverage. For a particular
product received by a particular user, “normally used” refers to a typical
or common use of that class of product, regardless of the status of the
particular user or of the way in which the particular user actually uses,
or expects or is expected to use, the product. A product is a consumer
product regardless of whether the product has substantial commercial,
industrial or non-consumer uses, unless such uses represent the only
significant mode of use of the product.

“Installation Information” for a User Product means any methods,
procedures, authorization keys, or other information required to install
and execute modified versions of a covered work in that User Product from a
modified version of its Corresponding Source. The information must suffice
to ensure that the continued functioning of the modified object code is in
no case prevented or interfered with solely because modification has been
made.

If you convey an object code work under this section in, or with, or
specifically for use in, a User Product, and the conveying occurs as part
of a transaction in which the right of possession and use of the User
Product is transferred to the recipient in perpetuity or for a fixed term
(regardless of how the transaction is characterized), the Corresponding
Source conveyed under this section must be accompanied by the Installation
Information. But this requirement does not apply if neither you nor any
third party retains the ability to install modified object code on the User
Product (for example, the work has been installed in ROM).

The requirement to provide Installation Information does not include a
requirement to continue to provide support service, warranty, or updates
for a work that has been modified or installed by the recipient, or for the
User Product in which it has been modified or installed. Access to a
network may be denied when the modification itself materially and adversely
affects the operation of the network or violates the rules and protocols
for communication across the network.

Corresponding Source conveyed, and Installation Information provided, in
accord with this section must be in a format that is publicly documented
(and with an implementation available to the public in source code form),
and must require no special password or key for unpacking, reading or
copying.

7. Additional Terms. “Additional permissions” are terms that supplement the
terms of this License by making exceptions from one or more of its
conditions. Additional permissions that are applicable to the entire
Program shall be treated as though they were included in this License, to
the extent that they are valid under applicable law. If additional
permissions apply only to part of the Program, that part may be used
separately under those permissions, but the entire Program remains governed
by this License without regard to the additional permissions.

When you convey a copy of a covered work, you may at your option remove any
additional permissions from that copy, or from any part of it. (Additional
permissions may be written to require their own removal in certain cases
when you modify the work.) You may place additional permissions on
material, added by you to a covered work, for which you have or can give
appropriate copyright permission.

Notwithstanding any other provision of this License, for material you add
to a covered work, you may (if authorized by the copyright holders of that
material) supplement the terms of this License with terms:

a) Disclaiming warranty or limiting liability differently from the terms of
sections 15 and 16 of this License; or b) Requiring preservation of
specified reasonable legal notices or author attributions in that material
or in the Appropriate Legal Notices displayed by works containing it; or c)
Prohibiting misrepresentation of the origin of that material, or requiring
that modified versions of such material be marked in reasonable ways as
different from the original version; or d) Limiting the use for publicity
purposes of names of licensors or authors of the material; or e) Declining
to grant rights under trademark law for use of some trade names,
trademarks, or service marks; or f) Requiring indemnification of licensors
and authors of that material by anyone who conveys the material (or
modified versions of it) with contractual assumptions of liability to the
recipient, for any liability that these contractual assumptions directly
impose on those licensors and authors. All other non-permissive additional
terms are considered “further restrictions” within the meaning of section
10. If the Program as you received it, or any part of it, contains a notice
stating that it is governed by this License along with a term that is a
further restriction, you may remove that term. If a license document
contains a further restriction but permits relicensing or conveying under
this License, you may add to a covered work material governed by the terms
of that license document, provided that the further restriction does not
survive such relicensing or conveying.

If you add terms to a covered work in accord with this section, you must
place, in the relevant source files, a statement of the additional terms
that apply to those files, or a notice indicating where to find the
applicable terms.

Additional terms, permissive or non-permissive, may be stated in the form
of a separately written license, or stated as exceptions; the above
requirements apply either way.

8. Termination. You may not propagate or modify a covered work except as
expressly provided under this License. Any attempt otherwise to propagate
or modify it is void, and will automatically terminate your rights under
this License (including any patent licenses granted under the third
paragraph of section 11).

However, if you cease all violation of this License, then your license from
a particular copyright holder is reinstated (a) provisionally, unless and
until the copyright holder explicitly and finally terminates your license,
and (b) permanently, if the copyright holder fails to notify you of the
violation by some reasonable means prior to 60 days after the cessation.

Moreover, your license from a particular copyright holder is reinstated
permanently if the copyright holder notifies you of the violation by some
reasonable means, this is the first time you have received notice of
violation of this License (for any work) from that copyright holder, and
you cure the violation prior to 30 days after your receipt of the notice.

Termination of your rights under this section does not terminate the
licenses of parties who have received copies or rights from you under this
License. If your rights have been terminated and not permanently
reinstated, you do not qualify to receive new licenses for the same
material under section 10.

9. Acceptance Not Required for Having Copies. You are not required to
accept this License in order to receive or run a copy of the Program.
Ancillary propagation of a covered work occurring solely as a consequence
of using peer-to-peer transmission to receive a copy likewise does not
require acceptance. However, nothing other than this License grants you
permission to propagate or modify any covered work. These actions infringe
copyright if you do not accept this License. Therefore, by modifying or
propagating a covered work, you indicate your acceptance of this License to
do so.

10. Automatic Licensing of Downstream Recipients. Each time you convey a
covered work, the recipient automatically receives a license from the
original licensors, to run, modify and propagate that work, subject to this
License. You are not responsible for enforcing compliance by third parties
with this License.

An “entity transaction” is a transaction transferring control of an
organization, or substantially all assets of one, or subdividing an
organization, or merging organizations. If propagation of a covered work
results from an entity transaction, each party to that transaction who
receives a copy of the work also receives whatever licenses to the work the
party's predecessor in interest had or could give under the previous
paragraph, plus a right to possession of the Corresponding Source of the
work from the predecessor in interest, if the predecessor has it or can get
it with reasonable efforts.

You may not impose any further restrictions on the exercise of the rights
granted or affirmed under this License. For example, you may not impose a
license fee, royalty, or other charge for exercise of rights granted under
this License, and you may not initiate litigation (including a cross-claim
or counterclaim in a lawsuit) alleging that any patent claim is infringed
by making, using, selling, offering for sale, or importing the Program or
any portion of it.

11. Patents. A “contributor” is a copyright holder who authorizes use under
this License of the Program or a work on which the Program is based. The
work thus licensed is called the contributor's “contributor version”.

A contributor's “essential patent claims” are all patent claims owned or
controlled by the contributor, whether already acquired or hereafter
acquired, that would be infringed by some manner, permitted by this
License, of making, using, or selling its contributor version, but do not
include claims that would be infringed only as a consequence of further
modification of the contributor version. For purposes of this definition,
“control” includes the right to grant patent sublicenses in a manner
consistent with the requirements of this License.

Each contributor grants you a non-exclusive, worldwide, royalty-free patent
license under the contributor's essential patent claims, to make, use,
sell, offer for sale, import and otherwise run, modify and propagate the
contents of its contributor version.

In the following three paragraphs, a “patent license” is any express
agreement or commitment, however denominated, not to enforce a patent (such
as an express permission to practice a patent or covenant not to sue for
patent infringement). To “grant” such a patent license to a party means to
make such an agreement or commitment not to enforce a patent against the
party.

If you convey a covered work, knowingly relying on a patent license, and
the Corresponding Source of the work is not available for anyone to copy,
free of charge and under the terms of this License, through a publicly
available network server or other readily accessible means, then you must
either (1) cause the Corresponding Source to be so available, or (2)
arrange to deprive yourself of the benefit of the patent license for this
particular work, or (3) arrange, in a manner consistent with the
requirements of this License, to extend the patent license to downstream
recipients. “Knowingly relying” means you have actual knowledge that, but
for the patent license, your conveying the covered work in a country, or
your recipient's use of the covered work in a country, would infringe one
or more identifiable patents in that country that you have reason to
believe are valid.

If, pursuant to or in connection with a single transaction or arrangement,
you convey, or propagate by procuring conveyance of, a covered work, and
grant a patent license to some of the parties receiving the covered work
authorizing them to use, propagate, modify or convey a specific copy of the
covered work, then the patent license you grant is automatically extended
to all recipients of the covered work and works based on it.

A patent license is “discriminatory” if it does not include within the
scope of its coverage, prohibits the exercise of, or is conditioned on the
non-exercise of one or more of the rights that are specifically granted
under this License. You may not convey a covered work if you are a party to
an arrangement with a third party that is in the business of distributing
software, under which you make payment to the third party based on the
extent of your activity of conveying the work, and under which the third
party grants, to any of the parties who would receive the covered work from
you, a discriminatory patent license (a) in connection with copies of the
covered work conveyed by you (or copies made from those copies), or (b)
primarily for and in connection with specific products or compilations that
contain the covered work, unless you entered into that arrangement, or that
patent license was granted, prior to 28 March 2007.

Nothing in this License shall be construed as excluding or limiting any
implied license or other defenses to infringement that may otherwise be
available to you under applicable patent law.

12. No Surrender of Others' Freedom. If 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 convey a covered work so as to satisfy
simultaneously your obligations under this License and any other pertinent
obligations, then as a consequence you may not convey it at all. For
example, if you agree to terms that obligate you to collect a royalty for
further conveying from those to whom you convey the Program, the only way
you could satisfy both those terms and this License would be to refrain
entirely from conveying the Program.

13. Use with the GNU Affero General Public License. Notwithstanding any
other provision of this License, you have permission to link or combine any
covered work with a work licensed under version 3 of the GNU Affero General
Public License into a single combined work, and to convey the resulting
work. The terms of this License will continue to apply to the part which is
the covered work, but the special requirements of the GNU Affero General
Public License, section 13, concerning interaction through a network will
apply to the combination as such.

14. Revised Versions of this License. The Free Software Foundation may
publish revised and/or new versions of the GNU 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 that a certain numbered version of the GNU General Public License
“or any later version” applies to it, you have the option of following the
terms and conditions either of that numbered version or of any later
version published by the Free Software Foundation. If the Program does not
specify a version number of the GNU General Public License, you may choose
any version ever published by the Free Software Foundation.

If the Program specifies that a proxy can decide which future versions of
the GNU General Public License can be used, that proxy's public statement
of acceptance of a version permanently authorizes you to choose that
version for the Program.

Later license versions may give you additional or different permissions.
However, no additional obligations are imposed on any author or copyright
holder as a result of your choosing to follow a later version.

15. Disclaimer of Warranty. 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.

16. Limitation of Liability. IN NO EVENT UNLESS REQUIRED BY APPLICABLE LAW
OR AGREED TO IN WRITING WILL ANY COPYRIGHT HOLDER, OR ANY OTHER PARTY WHO
MODIFIES AND/OR CONVEYS 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.

17. Interpretation of Sections 15 and 16. If the disclaimer of warranty and
limitation of liability provided above cannot be given local legal effect
according to their terms, reviewing courts shall apply local law that most
closely approximates an absolute waiver of all civil liability in
connection with the Program, unless a warranty or assumption of liability
accompanies a copy of the Program in return for a fee.

END OF TERMS AND CONDITIONS