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. 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". 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 NAMING perl-Software-License-OrLaterPack is official software name. However, in Perl world prefix "perl-" is redundant and not used. For example, on meta::cpan this software is named as Software-License-OrLaterPack. In the rest of the documentation shortened name Software-License-OrLaterPack is used as synonym for full name perl-Software-License-OrLaterPack. We are in the Perl world, aren't we? You may notice that name may be spelled with dashes (Software-License-OrLaterPack) or with double colons (Software::License::OrLaterPack). Strictly speaking, there is difference: the first one is software name, while the second is name of Perl package, but often these names are interchangeable especially if software consists of single package. FORMS You may face Software-License-OrLaterPack in *source* or *distribution* forms. If you are going to use GNU license with "or later" clause, you will likely be interested in *using* Software-License-OrLaterPack *distribution*. If you are going to *develop* (or *hack*) the Software-License-OrLaterPack itself, you will likely need the *source*, not distribution. Since Perl is an interpreting language, modules in the distribution *look* like sources. Actually, they are Perl source files. But they are not *actual* sources, because they are *built* (preprocessed or generated) by Dist-Zilla. How to distinguish source and distribution: * Source may contain Mercurial files and directories .hgignore, .hgtags, .hg/, while distribution should not. * Source should contain files dist.ini, weaver.ini, while distribution may not. * Source should *not* contain xt/ directory, while distribution should. * Name of source directory does *not* include version (e. g. Software-License-OrLaterPack), while name of distribution does (e. g. Software-License-OrLaterPack-0.007). SOURCE Software-License-OrLaterPack source is in Mercurial repository hosted on fedorapeople.org. To clone the entire repository: $ hg clone https://vandebugger.fedorapeople.org/hg/perl-Software-License-OrLaterPack Source Files Software-License-OrLaterPack source files usually include a comment near the top of the file: This file is part of perl-Software-License-OrLaterPack. Not all source files are included into distribution. Some source files are used at distribution build time only, and not required for installation. DISTRIBUTION Software-License-OrLaterPack distributions are published on CPAN . Generated Files Distribution may contain files preprocessed or generated by Dist-Zilla and its plugins. Some generated files are made from Software-License-OrLaterPack source, but some are generated from third-party templates. Files generated from third-party templates usually include a comment near the top of the file: This file was generated with NAME (where *NAME* is a name of the plugin generated the file). Such files are *not* part of Software-License-OrLaterPack source, and Software-License-OrLaterPack copyright and license are not applicable to such files. INSTALLING With cpanm cpanm tool is (probably) the easiest way to install distribution. It automates downloading, building, testing, installing, and uninstalling. To install the latest version from CPAN: $ cpanm Software::License::OrLaterPack To install a specific version (e. g. *0.007*) from CPAN: $ cpanm Software::License::OrLaterPack@0.007 To install locally available distribution (e. g. previously downloaded from CPAN or built from sources): $ cpanm ./Software-License-OrLaterPack-0.007.tar.gz To uninstall the distribution: $ cpanm -U Software::License::OrLaterPack Manually To install distribution tarball manually (let us assume you have version *0.007* of the distribution): $ tar xaf Software-License-OrLaterPack-0.007.tar.gz $ cd Software-License-OrLaterPack-0.007 $ perl Build.PL $ ./Build build $ ./Build test $ ./Build install See Also How to install CPAN modules HACKING For hacking, you will need Mercurial, Perl interpreter and Dist-Zilla (with some plugins), and likely cpanm to install missed parts. Clone the repository first: $ hg clone https://vandebugger.fedorapeople.org/hg/perl-Software-License-OrLaterPack $ cd perl-Software-License-OrLaterPack To build a distribution from the source, run: $ dzil build If required Dist-Zilla plugins are missed, dzil tool will warn you and show the command to install all the required plugins, e. g.: Required plugin Dist::Zilla::Plugin::Test::EOL isn't installed. Run 'dzil authordeps' to see a list of all required plugins. You can pipe the list to your CPAN client to install or update them: dzil authordeps --missing | cpanm To run the tests: $ dzil test To run all the tests, including release tests: $ dzil test --release To install the distribution: $ dzil install or $ cpanm ./Software-License-OrLaterPack-VERSION.tar.gz where *VERSION* is a version of built distribution. To clean the directory: $ dzil clean DOCUMENTATION Online The easiest way is browsing the documentation online at meta::cpan . Locally Installed If you have the distribution installed, use perldoc tool to browse locally installed documentation: $ perldoc Software::License::OrLaterPack::Manual $ perldoc Software::License::OrLaterPack Built from Source Build Software-License-OrLaterPack first (see "HACKING"), then: $ cd Software-License-OrLaterPack-VERSION $ perldoc Software::License::OrLaterPack::Manual $ perldoc Software::License::OrLaterPack where *VERSION* is a version of built distribution. FEEDBACK CPAN Request Tracker The quickest way to report a bug in Software-License-OrLaterPack is by sending email to bug-Software-License-OrLaterPack [at] rt.cpan.org. CPAN request tracker can be used via web interface also: Browse bugs Browsing bugs does not require authentication. Report bugs You need to be a CPAN author, have a BitCard account, or OpenID in order to report bugs via the web interface. (On 2015-04-27 I have logged in successfully with my LiveJournal OpenID, but my Google OpenID did not work for CPAN. I did not check other OpenID providers.) Send Email to Author As a last resort, send email to author: Van de Bugger . Please start message subject with "perl-Software-License-OrLaterPack:". GLOSSARY CPAN Comprehensive Perl Archive Network, a large collection of Perl software and documentation. See cpan.org , What is CPAN? . Distribution Tarball, containing Perl modules and accompanying files (documentation, metainfo, tests). Usually distributions are uploaded to CPAN, and can be installed with dedicated tools (cpan, cpanm, and others). Module Perl library file, usually with .pm suffix. Usually contains one package. See perlmod . Package Perl language construct. See package and perlmod .