Version 3, 29 June 2007

Copyright © 2007 Free Software Foundation, Inc. <>

Everyone is permitted to copy and distribute verbatim copies of this license

document, but changing it is not allowed.


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

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For the developers' and authors' protection, the GPL clearly explains that there is

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Some devices are designed to deny users access to install or run modified versions of

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Finally, every program is threatened constantly by software patents. States should

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


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

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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

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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

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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


A “Standard Interface” means an interface that either is an official

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The “System Libraries” of an executable work include anything, other than

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A “Major Component”, in this context, means a major essential component

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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

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output from running a covered work is covered by this License only if the output,

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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

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them from making any copies of your copyrighted material outside their relationship

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Conveying under any other circumstances is permitted solely under the conditions

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No covered work shall be deemed part of an effective technological measure under any

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adopted on 20 December 1996, or similar laws prohibiting or restricting circumvention

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When you convey a covered work, you waive any legal power to forbid circumvention of

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intention to limit operation or modification of the work as a means of enforcing,

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4. Conveying Verbatim Copies.

You may convey verbatim copies of the Program's source code as you receive it, in any

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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

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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


  • 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

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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


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


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.








16. Limitation of Liability.









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.


How to Apply These Terms to Your New Programs

If you develop a new program, and you want it to be of the greatest possible use to

the public, the best way to achieve this is to make it free software which everyone

can redistribute and change under these terms.

To do so, attach the following notices to the program. It is safest to attach them

to the start of each source file to most effectively state the exclusion of warranty;

and each file should have at least the “copyright” line and a pointer to

where the full notice is found.

<one line to give the program's name and a brief idea of what it does.>

Copyright (C) <year>  <name of author>

This program is free software: you can redistribute it and/or modify

it under the terms of the GNU General Public License as published by

the Free Software Foundation, either version 3 of the License, or

(at your option) any later version.

This program is distributed in the hope that it will be useful,

but WITHOUT ANY WARRANTY; without even the implied warranty of


GNU General Public License for more details.

You should have received a copy of the GNU General Public License

along with this program.  If not, see <>.

Also add information on how to contact you by electronic and paper mail.

If the program does terminal interaction, make it output a short notice like this

when it starts in an interactive mode:

<program>  Copyright (C) <year>  <name of author>

This program comes with ABSOLUTELY NO WARRANTY; for details type 'show w'.

This is free software, and you are welcome to redistribute it

under certain conditions; type 'show c' for details.

The hypothetical commands 'show w' and 'show c' should show the appropriate parts of

the General Public License. Of course, your program's commands might be different;

for a GUI interface, you would use an “about box”.

You should also get your employer (if you work as a programmer) or school, if any, to

sign a “copyright disclaimer” for the program, if necessary. For more

information on this, and how to apply and follow the GNU GPL, see


The GNU General Public License does not permit incorporating your program into

proprietary programs. If your program is a subroutine library, you may consider it

more useful to permit linking proprietary applications with the library. If this is

what you want to do, use the GNU Lesser General Public License instead of this

License. But first, please read