ESP8266-IOT-timer/COPYING.md

# GNU GENERAL PUBLIC LICENSE

Version 3, 29 June 2007

Copyright (C) 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/licenses/why-not-lgpl.html>.