perldoc ExtUtils::MakeMaker |grep -A3 -i license

    LICENSE
      The licensing terms of your distribution. Generally its "perl" f
+or the
      same license as Perl itself.

      See Module::Build::API for the list of options.

--
LICENSE
    This program is free software; you can redistribute it and/or modi
+fy it
    under the same terms as Perl itself.
[download]

perldoc Module::Build::API |grep -A3 -i license

        create_license
            [version 0.31]

            This parameter tells Module::Build to automatically create
+ a
            LICENSE file at the top level of your distribution, contai
+ning
            the full text of the author's chosen license. This require
+s
            "Software::License" on the author's machine, and further
            requires that the "license" parameter specifies a license 
+that
            it knows about.

        create_makefile_pl
--
        license
            [version 0.07]

            Specifies the licensing terms of your distribution.
--
            Software::License subclass name (e.g. 'Apache_2_0') instea
+d of
            one of the keys below.

            The legacy list of valid license values include:

            apache
                The distribution is licensed under the Apache License,
                Version 2.0 (<http://apache.org/licenses/LICENSE-2.0>)
+.

            apache_1_1
                The distribution is licensed under the Apache Software
                License, Version 1.1
                (<http://apache.org/licenses/LICENSE-1.1>).

            artistic
                The distribution is licensed under the Artistic Licens
+e, as
                specified by the Artistic file in the standard Perl
                distribution.

--
                The distribution is licensed under the Artistic 2.0 Li
+cense
                (<http://opensource.org/licenses/artistic-license-2.0.
+php>.)

            bsd The distribution is licensed under the BSD License
                (<http://www.opensource.org/licenses/bsd-license.php>)
+.

            gpl The distribution is licensed under the terms of the GN
+U
                General Public License
                (<http://www.opensource.org/licenses/gpl-license.php>)
+.

            lgpl
                The distribution is licensed under the terms of the GN
+U
                Lesser General Public License
                (<http://www.opensource.org/licenses/lgpl-license.php>
+).

            mit The distribution is licensed under the MIT License
                (<http://opensource.org/licenses/mit-license.php>).

            mozilla
                The distribution is licensed under the Mozilla Public
                License. (<http://opensource.org/licenses/mozilla1.0.p
+hp> or
                <http://opensource.org/licenses/mozilla1.1.php>)

            open_source
                The distribution is licensed under some other Open Sou
+rce
                Initiative-approved license listed at
                <http://www.opensource.org/licenses/>.

            perl
                The distribution may be copied and redistributed under
+ the
--
                license, in which the user may choose between either t
+he GPL
                or the Artistic license.

            restrictive
                The distribution may not be redistributed without spec
+ial
--
                The distribution is licensed under a license that is n
+ot
                approved by www.opensource.org but that allows distrib
+ution
                without restrictions.

            Note that you must still include the terms of your license
+ in
            your code and documentation - this field only sets the
            information that is included in distribution metadata to l
+et
            automated tools figure out your licensing restrictions. Hu
+mans
--
            You may also use a license type of "unknown" if you don't 
+wish
            to specify your terms in the metadata.

            Also see the "create_license" parameter.

        meta_add
            [version 0.28]
--
        core properties, such as "module_name" and "license", are defi
+ned
        using this class method.

        The first argument to "add_property()" is always the name of t
+he
--
    create_license()
    create_makefile_pl()
    create_packlist()
    create_readme()
--
    license()
    magic_number()
    mb_version()
    meta_add()
[download]

See also Software::License