qusal/LICENSES/GPL-3.0-or-later.txt

GNU GENERAL PUBLIC LICENSE Version 3, 29 June 2007

Copyright © 2007 Free Software Foundation, Inc. <https://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

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
     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the 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 <https://www.gnu.org/licenses/>.

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
<https://www.gnu.org/licenses/>.

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
<https://www.gnu.org/philosophy/why-not-lgpl.html>.