Ubuntu Manpage: Software::License::OrLaterPack - Use GNU license with "or later" clause

Provided by: libsoftware-license-orlaterpack-perl_0.10.2-2_all

NAME

       Software::License::OrLaterPack - Use GNU license with "or later" clause

VERSION

       Version v0.10.2, released on 2016-10-10 22:17 UTC.

WHAT?

       "Software-License-OrLaterPack" (or just "OrLaterPack" for brevity) is an add-on for "Software-License", a
       set of licenses with "or later" clause (like "GPL_3::or_later"). It allows Perl developers (who use
       "Dist-Zilla") to release their work under the terms of a License version N or (at user option) any later
       version.

       This is "OrLaterPack" user manual. Read this if you want to use GNU license with "or later" clause.

       If you are going to hack or extend "OrLaterPack" read module documentation, e. g.
       Software::License::GPL_3::or_later. General topics like getting source, building, installing, bug
       reporting and some others are covered in the README file.

SYNOPSIS

DESCRIPTION

All "or later" are just subclasses of corresponding base license classes. For example,
"Software::License::GPL_3::or_later" is a subclass of "Software::License::GPL_3", so any "or later"
license can be used like any other license. For example, in your dist.ini file:

license = GPL_3::or_later

However, licenses in the pack introduce few features not found in base classes.

Program Name
"Software::License" constructor accepts hashref as the only argument:

$lic = Software::License::GPL_3::or_later->new( {
holder => 'John Doe',
year => '2010',
} );

"Software::License" documents two keys "holder" and "year" shown in example. However, "Software::License"
constructor just (re)blesses passed hashref to the package, keeping all the hash keys and values intact,
so you can pass more arguments to the constructor.

"OrLaterPack" licenses use two more keys "program" and "Program":

$lic = Software::License::GPL_3::or_later->new( {
holder => 'John Doe',
year => '2010',
program => 'assa',
Program => 'Assa',
} );

These values are used as program name instead of generic "this program" in license notice, for example:

Assa is free software: you can redistribute it and/or modify itX

"program" key is used in the middle of sentence, "Program" is used if program name starts a sentence. You
may specify either one or both keys. If only one key specified, it is used in all the occurrences
regardless of its position within a sentence.

Note: At time of writing, these keys are used only by licenses from "OrLaterPack". You can safely pass
them to constructor of any license, it does not hurt but keys will not be used.

When using "Dist::Zilla" you just specify few options, and "Dist::Zilla" does all the work on behalf of
you:

name = Assa
license = GPL_3::or_later
copyright_holder = John Doe
copyright_year = 2010

Program name is specified, but "Dist::Zilla" does not pass it to license object constructor. Patch for
"Dist::Zilla" submitted but not yet applied. Meanwhile, you can hack it with little help from "Hook"
plugin:

name = Assa
license = GPL_3::or_later
copyright_holder = John Doe
copyright_year = 2010
[Hook::Init]
. = $dist->license->{ program } = $dist->name;
; Voila: license has `program` key now.
...

For accessing these keys, "OrLaterPack" introduced two methods: "program" and "Program". They are
convenient because you should not worry if the key was specified or not: a method returns best available
variant of program name. For example, if "program" key was not passed to the constructor, "$self->{
program }" will return "undef", while "$self->program" will return value of "Program" key, if it was
specified, or "this program" as the last resort. However, these methods are not defined in base class and
can be invoked only on a license from "OrLaterPack".

Short License Notice
Standard GNU license notice consists of 3 paragraphs (more than 100 words and 600 characters). It is ok
for the program documentation, but it far too long to be printed in the beginning of interactive session.
For latter purpose FSF recommends to use short notice like this one:

Copyright (C) 2010 John Doe
License GPLv3+: GNU General Public License version 3 or later.
This is free software: you are free to change and redistribute it.
There is NO WARRANTY, to the extent permitted by law.

To get short license notice, pass 'short' argument to the "notice" method:

$lic->notice( 'short' );

At time of writing, 'short' argument is respected only by licenses in "orLaterPack". Other licenses
ignore the arguments and return ordinary license note.

Note: This feature is considered experimental now.

WHY?

       "Dist-Zilla" is a popular tool for building CPAN distributions. Build process is controlled by dist.ini,
       "Dist-Zilla" configuration file. A distribution author can specify license covering his work by using
       "license" option in dist.ini file:

           license = NAME

       where NAME is a name of module from Software::License hierarchy.

       "Software-License" is shipped with a set of popular licenses, from "Apache_1_1" to "Zlib", including GNU
       licenses (GPL), including their "Affero" and "Lesser" variants.

       So, if a developer wants to release his work under the terms of the GPL version 3, he should write in his
       dist.ini:

           license = GPL_3

       However, Free Software Foundation recommends using clause "license version N or (at your option) any
       later version" <https://www.gnu.org/licenses/gpl-faq.html#VersionThreeOrLater>. Unfortunately,
       "Software-License" distribution does not supply (out of the box) a way to express such clause.

       "OrLaterPack" fulfills the lack. If "OrLaterPack" is installed, a developer can specify in his dist.ini:

           license = GPL_3::or_later

       In "dist.ini":

           name             = Foo-Bar
           version          = 0.001
           author           = John Doe <john.doe@example.com>
           license          = GPL_3::or_later
               ; or another license, see the list of provided licenses
           copyright_holder = John Doe
           copyright_year   = 2015
           X

       Direct usage:

           use Software::License::GPL_3::or_later;
               # or another license, see the list of provided licenses
           my $lic = Software::License::GPL_3::or_later->new( {
               holder  => 'John Doe',
               year    => '2010',
               program => 'Assa',
           } );
           $lic->abbr;     # returns 'GPLv3+'
           $lic->notice;   # Copyright statement and 3-paragraph GNU license notice
           X

LIST OF PROVIDED LICENSES

       Software::License::AGPL_3::or_later
       Software::License::GPL_1::or_later
       Software::License::GPL_2::or_later
       Software::License::GPL_3::or_later
       Software::License::LGPL_2_1::or_later
       Software::License::LGPL_3_0::or_later

CAVEATS

       CPAN::Meta::Spec hardcodes the list of "valid" licenses. In version 2.150001 of the module there are no
       "upgradable" GNU licenses, so in CPAN the GPLv3+ will look as ordinal GPLv3 ("gpl_3"), and so on.

AUTHOR

       Van de Bugger <van.de.bugger@gmail.com>

COPYRIGHT AND LICENSE

       Copyright (C) 2015 Van de Bugger

       License GPLv3+: The GNU General Public License version 3 or later
       <http://www.gnu.org/licenses/gpl-3.0.txt>.

       This is free software: you are free to change and redistribute it. There is NO WARRANTY, to the extent
       permitted by law.