+=encoding utf8
+
=head1 NAME
-perlpolicy - Various and sundry policies and commitments related to the perl core
+perlpolicy - Various and sundry policies and commitments related to the Perl core
=head1 DESCRIPTION
policies about how the Perl 5 Porters collectively develop and maintain
the Perl core.
+=head1 GOVERNANCE
+
+=head2 Perl 5 Porters
+
+Subscribers to perl5-porters (the porters themselves) come in several flavours.
+Some are quiet curious lurkers, who rarely pitch in and instead watch
+the ongoing development to ensure they're forewarned of new changes or
+features in Perl. Some are representatives of vendors, who are there
+to make sure that Perl continues to compile and work on their
+platforms. Some patch any reported bug that they know how to fix,
+some are actively patching their pet area (threads, Win32, the regexp
+-engine), while others seem to do nothing but complain. In other
+words, it's your usual mix of technical people.
+
+Over this group of porters presides Larry Wall. He has the final word
+in what does and does not change in any of the Perl programming languages.
+These days, Larry spends most of his time on Perl 6, while Perl 5 is
+shepherded by a "pumpking", a porter responsible for deciding what
+goes into each release and ensuring that releases happen on a regular
+basis.
+
+Larry sees Perl development along the lines of the US government:
+there's the Legislature (the porters), the Executive branch (the
+-pumpking), and the Supreme Court (Larry). The legislature can
+discuss and submit patches to the executive branch all they like, but
+the executive branch is free to veto them. Rarely, the Supreme Court
+will side with the executive branch over the legislature, or the
+legislature over the executive branch. Mostly, however, the
+legislature and the executive branch are supposed to get along and
+work out their differences without impeachment or court cases.
+
+You might sometimes see reference to Rule 1 and Rule 2. Larry's power
+as Supreme Court is expressed in The Rules:
+
+=over 4
+
+=item 1
+
+Larry is always by definition right about how Perl should behave.
+This means he has final veto power on the core functionality.
+
+=item 2
+
+Larry is allowed to change his mind about any matter at a later date,
+regardless of whether he previously invoked Rule 1.
+
+=back
+
+Got that? Larry is always right, even when he was wrong. It's rare
+to see either Rule exercised, but they are often alluded to.
+
+=head1 MAINTENANCE AND SUPPORT
+
+Perl 5 is developed by a community, not a corporate entity. Every change
+contributed to the Perl core is the result of a donation. Typically, these
+donations are contributions of code or time by individual members of our
+community. On occasion, these donations come in the form of corporate
+or organizational sponsorship of a particular individual or project.
+
+As a volunteer organization, the commitments we make are heavily dependent
+on the goodwill and hard work of individuals who have no obligation to
+contribute to Perl.
+
+That being said, we value Perl's stability and security and have long
+had an unwritten covenant with the broader Perl community to support
+and maintain releases of Perl.
+
+This document codifies the support and maintenance commitments that
+the Perl community should expect from Perl's developers:
+=over
+
+=item *
+
+We "officially" support the two most recent stable release series. 5.14.x
+and earlier are now out of support. As of the release of 5.20.0, we will
+"officially" end support for Perl 5.16.x, other than providing security
+updates as described below.
+
+=item *
+
+To the best of our ability, we will attempt to fix critical issues
+in the two most recent stable 5.x release series. Fixes for the
+current release series take precedence over fixes for the previous
+release series.
+
+=item *
+
+To the best of our ability, we will provide "critical" security patches
+/ releases for any major version of Perl whose 5.x.0 release was within
+the past three years. We can only commit to providing these for the
+most recent .y release in any 5.x.y series.
+
+=item *
+
+We will not provide security updates or bug fixes for development
+releases of Perl.
+
+=item *
+
+We encourage vendors to ship the most recent supported release of
+Perl at the time of their code freeze.
+
+=item *
+
+As a vendor, you may have a requirement to backport security fixes
+beyond our 3 year support commitment. We can provide limited support and
+advice to you as you do so and, where possible will try to apply
+those patches to the relevant -maint branches in git, though we may or
+may not choose to make numbered releases or "official" patches
+available. Contact us at E<lt>perl5-security-report@perl.orgE<gt>
+to begin that process.
+
+=back
+
+=head1 BACKWARD COMPATIBILITY AND DEPRECATION
+
+Our community has a long-held belief that backward-compatibility is a
+virtue, even when the functionality in question is a design flaw.
+
+We would all love to unmake some mistakes we've made over the past
+decades. Living with every design error we've ever made can lead
+to painful stagnation. Unwinding our mistakes is very, very
+difficult. Doing so without actively harming our users is
+nearly impossible.
+
+Lately, ignoring or actively opposing compatibility with earlier versions
+of Perl has come into vogue. Sometimes, a change is proposed which
+wants to usurp syntax which previously had another meaning. Sometimes,
+a change wants to improve previously-crazy semantics.
+
+Down this road lies madness.
+
+Requiring end-user programmers to change just a few language constructs,
+even language constructs which no well-educated developer would ever
+intentionally use is tantamount to saying "you should not upgrade to
+a new release of Perl unless you have 100% test coverage and can do a
+full manual audit of your codebase." If we were to have tools capable of
+reliably upgrading Perl source code from one version of Perl to another,
+this concern could be significantly mitigated.
+
+We want to ensure that Perl continues to grow and flourish in the coming
+years and decades, but not at the expense of our user community.
+
+Existing syntax and semantics should only be marked for destruction in
+very limited circumstances. If they are believed to be very rarely used,
+stand in the way of actual improvement to the Perl language or perl
+interpreter, and if affected code can be easily updated to continue
+working, they may be considered for removal. When in doubt, caution
+dictates that we will favor backward compatibility. When a feature is
+deprecated, a statement of reasoning describing the decision process
+will be posted, and a link to it will be provided in the relevant
+perldelta documents.
+
+Using a lexical pragma to enable or disable legacy behavior should be
+considered when appropriate, and in the absence of any pragma legacy
+behavior should be enabled. Which backward-incompatible changes are
+controlled implicitly by a 'use v5.x.y' is a decision which should be
+made by the pumpking in consultation with the community.
+
+Historically, we've held ourselves to a far higher standard than
+backward-compatibility -- bugward-compatibility. Any accident of
+implementation or unintentional side-effect of running some bit of code
+has been considered to be a feature of the language to be defended with
+the same zeal as any other feature or functionality. No matter how
+frustrating these unintentional features may be to us as we continue
+to improve Perl, these unintentional features often deserve our
+protection. It is very important that existing software written in
+Perl continue to work correctly. If end-user developers have adopted a
+bug as a feature, we need to treat it as such.
+
+New syntax and semantics which don't break existing language constructs
+and syntax have a much lower bar. They merely need to prove themselves
+to be useful, elegant, well designed, and well tested. In most cases,
+these additions will be marked as I<experimental> for some time. See
+below for more on that.
+
+=head2 Terminology
+
+To make sure we're talking about the same thing when we discuss the removal
+of features or functionality from the Perl core, we have specific definitions
+for a few words and phrases.
+
+=over
+
+=item experimental
+
+If something in the Perl core is marked as B<experimental>, we may change
+its behaviour, deprecate or remove it without notice. While we'll always
+do our best to smooth the transition path for users of experimental
+features, you should contact the perl5-porters mailinglist if you find
+an experimental feature useful and want to help shape its future.
+
+Experimental features must be experimental in two stable releases before being
+marked non-experimental. Experimental features will only have their
+experimental status revoked when they no longer have any design-changing bugs
+open against them and when they have remained unchanged in behavior for the
+entire length of a development cycle. In other words, a feature present in
+v5.20.0 may be marked no longer experimental in v5.22.0 if and only if its
+behavior is unchanged throughout all of v5.21.
+
+=item deprecated
+
+If something in the Perl core is marked as B<deprecated>, we may remove it
+from the core in the future, though we might not. Generally, backward
+incompatible changes will have deprecation warnings for two release
+cycles before being removed, but may be removed after just one cycle if
+the risk seems quite low or the benefits quite high.
+
+As of
+Perl 5.12, deprecated features and modules warn the user as they're used.
+When a module is deprecated, it will also be made available on CPAN.
+Installing it from CPAN will silence deprecation warnings for that module.
+
+If you use a deprecated feature or module and believe that its removal from
+the Perl core would be a mistake, please contact the perl5-porters
+mailinglist and plead your case. We don't deprecate things without a good
+reason, but sometimes there's a counterargument we haven't considered.
+Historically, we did not distinguish between "deprecated" and "discouraged"
+features.
+
+=item discouraged
+
+From time to time, we may mark language constructs and features which we
+consider to have been mistakes as B<discouraged>. Discouraged features
+aren't currently candidates for removal, but
+we may later deprecate them if they're found to stand in the way of a
+significant improvement to the Perl core.
+
+=item removed
+
+Once a feature, construct or module has been marked as deprecated, we
+may remove it from the Perl core. Unsurprisingly,
+we say we've B<removed> these things. When a module is removed, it will
+no longer ship with Perl, but will continue to be available on CPAN.
+
+=back
+
+=head1 MAINTENANCE BRANCHES
+
+New releases of maint should contain as few changes as possible.
+If there is any question about whether a given patch might merit
+inclusion in a maint release, then it almost certainly should not
+be included.
+
+The following types of change may be considered acceptable, as long as they do
+not also fall into any of the "unacceptable" categories set out below:
+
+=over
+
+=item *
+
+Patches that fix CVEs or security issues. These changes should
+be run through the perl5-security-report@perl.org mailing list
+rather than applied directly.
+
+=item *
+
+Patches that fix crashing bugs, assertion failures and
+memory corruption that do not otherwise change Perl's
+functionality or negatively impact performance.
+
+=item *
+
+Patches that fix regressions in perl's behavior relative to previous
+releases, no matter how old the regression, since some people may
+upgrade from very old versions of perl to the latest version.
+
+=item *
+
+Patches that fix anything which prevents or seriously impacts the build
+or installation of perl.
+
+=item *
+
+Portability fixes, such as changes to Configure and the files in
+the hints/ folder.
+
+=item *
+
+Minimal patches that fix platform-specific test failures.
+
+=item *
+
+Documentation updates that correct factual errors, explain significant
+bugs or deficiencies in the current implementation, or fix broken markup.
+
+=item *
+
+Updates to dual-life modules should consist of minimal patches to
+fix crashing bugs or security issues (as above). Any changes made to
+dual-life modules for which CPAN is canonical should be coordinated with
+the upstream author.
+
+=back
+
+The following types of change are NOT acceptable:
+
+=over
+
+=item *
+
+Patches that break binary compatibility. (Please talk to a pumpking.)
+
+=item *
+
+Patches that add or remove features.
+
+=item *
+
+Patches that add new warnings or errors or deprecate features.
+
+=item *
+
+Ports of Perl to a new platform, architecture or OS release that
+involve changes to the implementation.
+
+=item *
+
+New versions of dual-life modules should NOT be imported into maint.
+Those belong in the next stable series.
+
+=back
+
+=head2 Getting changes into a maint branch
+
+Historically, only the pumpking cherry-picked changes from bleadperl
+into maintperl. This has scaling problems. At the same time,
+maintenance branches of stable versions of Perl need to be treated with
+great care. To that end, as of Perl 5.12, we have a new process for
+maint branches.
+
+Any committer may cherry-pick any commit from blead to a maint branch if
+they send mail to perl5-porters announcing their intent to cherry-pick
+a specific commit along with a rationale for doing so and at least two
+other committers respond to the list giving their assent. (This policy
+applies to current and former pumpkings, as well as other committers.)
=head1 CONTRIBUTED MODULES
From time to time, a script, module, or set of modules (hereafter referred
to simply as a "module") will prove so widely useful and/or so integral to
the correct functioning of Perl itself that it should be distributed with
-Perl core. This should never be done without the author's explicit
+the Perl core. This should never be done without the author's explicit
consent, and a clear recognition on all parts that this means the module
is being distributed under the same terms as Perl itself. A module author
should realize that inclusion of a module into the Perl core will
=over
-=item * The version of the module in the core should still be considered the
- work of the original author. All patches, bug reports, and so forth
- should be fed back to them. Their development directions should be
- respected whenever possible.
+=item *
+
+The version of the module in the Perl core should still be considered the
+work of the original author. All patches, bug reports, and so
+forth should be fed back to them. Their development directions
+should be respected whenever possible.
=item *
If the author's vision of the future of their module is sufficiently
different from the vision of the pumpkin holder and perl5-porters as a
whole so as to cause serious problems for Perl, the pumpkin holder may
-choose to formally fork the version of the module in the core from the
+choose to formally fork the version of the module in the Perl core from the
one maintained by the author. This should not be done lightly and
-should *always* if at all possible be done only after direct input
+should B<always> if at all possible be done only after direct input
from Larry. If this is done, it must then be made explicit in the
-module as distributed with Perl core that it is a forked version and
+module as distributed with the Perl core that it is a forked version and
that while it is based on the original author's work, it is no longer
maintained by them. This must be noted in both the documentation and
in the comments in the source of the module.
necessary, and certainly no more drastic measure should be used until
every avenue of communication and discussion has failed.
+
+=head1 DOCUMENTATION
+
+Perl's documentation is an important resource for our users. It's
+incredibly important for Perl's documentation to be reasonably coherent
+and to accurately reflect the current implementation.
+
+Just as P5P collectively maintains the codebase, we collectively
+maintain the documentation. Writing a particular bit of documentation
+doesn't give an author control of the future of that documentation.
+At the same time, just as source code changes should match the style
+of their surrounding blocks, so should documentation changes.
+
+Examples in documentation should be illustrative of the concept
+they're explaining. Sometimes, the best way to show how a
+language feature works is with a small program the reader can
+run without modification. More often, examples will consist
+of a snippet of code containing only the "important" bits.
+The definition of "important" varies from snippet to snippet.
+Sometimes it's important to declare C<use strict> and C<use warnings>,
+initialize all variables and fully catch every error condition.
+More often than not, though, those things obscure the lesson
+the example was intended to teach.
+
+As Perl is developed by a global team of volunteers, our
+documentation often contains spellings which look funny
+to I<somebody>. Choice of American/British/Other spellings
+is left as an exercise for the author of each bit of
+documentation. When patching documentation, try to emulate
+the documentation around you, rather than changing the existing
+prose.
+
+In general, documentation should describe what Perl does "now" rather
+than what it used to do. It's perfectly reasonable to include notes
+in documentation about how behaviour has changed from previous releases,
+but, with very few exceptions, documentation isn't "dual-life" --
+it doesn't need to fully describe how all old versions used to work.
+
+=head1 STANDARDS OF CONDUCT
+
+The official forum for the development of perl is the perl5-porters mailing
+list, mentioned above, and its bugtracker at rt.perl.org. All participants in
+discussion there are expected to adhere to a standard of conduct.
+
+=over 4
+
+=item *
+
+Always be civil.
+
+=item *
+
+Heed the moderators.
+
+=back
+
+Civility is simple: stick to the facts while avoiding demeaning remarks and
+sarcasm. It is not enough to be factual. You must also be civil. Responding
+in kind to incivility is not acceptable.
+
+If the list moderators tell you that you are not being civil, carefully
+consider how your words have appeared before responding in any way. You may
+protest, but repeated protest in the face of a repeatedly reaffirmed decision
+is not acceptable.
+
+Unacceptable behavior will result in a public and clearly identified warning.
+Repeated unacceptable behavior will result in removal from the mailing list and
+revocation of rights to update rt.perl.org. The first removal is for one
+month. Subsequent removals will double in length. After six months with no
+warning, a user's ban length is reset. Removals, like warnings, are public.
+
+The list of moderators will be public knowledge. At present, it is:
+Aaron Crane, Andy Dougherty, Ricardo Signes, Steffen Müller.
+
=head1 CREDITS
-Social Contract about Contributed Modules originall by Russ Allbery E<lt>rra@stanford.eduE<gt> and the perl5-porters.
+"Social Contract about Contributed Modules" originally by Russ Allbery E<lt>rra@stanford.eduE<gt> and the perl5-porters.
https://perl5.git.perl.org / perl5.git / blobdiff