PERLPOLICY(1perl)

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version 5.44.0 · 2 versions
, in arch rolling

🎀 PERLPOLICY 🎀

(that's perlpolicy, from section 1perl of the Perl Programmers Reference Guide)

okay so before we even start: this is the master doc, the main character of policy paperwork, the one that records all the written policies about how the Perl 5 Porters collectively develop and maintain the Perl core. yes bestie, all of them. grab a snack 🍓

✨ NAME ✨

perlpolicy — Various and sundry policies and commitments related to the Perl core 💖

📜 DESCRIPTION 📜

This document is the master document, the group chat pinned message, the one that records all written policies about how the Perl 5 Porters collectively develop and maintain the Perl core. periodt.

👑 GOVERNANCE 👑

🧚 Perl 5 Porters 🧚

So, the subscribers to perl5-porters (aka the porters themselves) come in several flavours, and honestly? it's giving a whole buffet:

  • some are quiet curious lurkers 👀 — they rarely pitch in, they just watch the ongoing development so they're forewarned of new changes or features in Perl
  • some are representatives of vendors 🏢 — they're there to make sure 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. iconic, honestly.

Among these people are the core Perl team. These are trusted volunteers involved in the ongoing development of the Perl language and interpreter. They are not required to be language developers or committers. lowkey a vibe.

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 Raku, while Perl 5 is shepherded by a steering council of porters 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, represented by the core team), the Executive branch (the steering council), 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. 💀 no impeachment arc pls

You might sometimes see reference to Rule 1 and Rule 2. Larry's power as Supreme Court is expressed in The Rules:

  1. Larry is always by definition right about how Perl should behave. This means he has final veto power on the core functionality.
  2. Larry is allowed to change his mind about any matter at a later date, regardless of whether he previously invoked Rule 1.

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. 👑

For the specifics on how the members of the core team and steering council are elected or rotated, consult perlgov, which spells it all out in detail. iykyk.

🌈 VERSIONING 🌈

Perl uses a "5.X.Y" version numbering scheme. here's the whole tea:

  • Even-numbered X values (e.g., 5.40, 5.42) are stable release series. 🫶
  • Odd-numbered X values (e.g., 5.41, 5.43) are development release series, leading up to the next stable release. Development releases get a new Y increment roughly every month. 🦋
  • Y increments in stable series (e.g., 5.42.1, 5.42.2) are maintenance releases that contain critical bug fixes and security patches only. 🔒

A new stable release series is typically produced once a year. ⭐

🛠️ MAINTENANCE AND SUPPORT 🛠️

These are the "officially" supported perl versions as of the release of Perl 5.42:

Version track    Start date      Support status
-------------    -----------     --------------
5.44.x           2026-Jul-15     Full support (current stable)
5.42.x           2025-Jul-03     Full support (previous stable)
5.40.x           2024-Jun-09     Security fixes only
[ Any older stable release ]     End of life

Perl 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. fr fr.

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:

  • 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. 🔥
  • 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. 🔒
  • We will not provide security updates or bug fixes for development releases of Perl. 🚫
  • We encourage vendors to ship the most recent supported release of Perl at the time of their code freeze. 📦
  • 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 we 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. See "SECURITY VULNERABILITY CONTACT INFORMATION" in perlsec for details on how to begin that process. 🌈
bestie this is only part 1 of 4, so don't go anywhere — there is so much more policy left to slay 💖

💖 BACKWARD COMPATIBILITY AND DEPRECATION 💖

okay so bestie, our community has had a long-held belief that backward-compatibility is a virtue, even when the functionality in question is a design flaw. periodt. 💅

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 steering council 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 experimental for some time. See below for more on that. ✨

🌸 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. 🎀

experimental

If something in the Perl core is marked as 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. 🦋

deprecated

If something in the Perl core is marked as 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. 🥺

discouraged

From time to time, we may mark language constructs and features which we consider to have been mistakes as 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. 🚫

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 removed these things. When a module is removed, it will no longer ship with Perl, but will continue to be available on CPAN. 🗑️

✨ MAINTENANCE BRANCHES ✨

so like. new releases of maintenance branches?? they're only allowed to have changes that fall into one of the "acceptable" categories listed below, and they absolutely must NOT have anything from the "unacceptable" list. and yes bestie, those two lists can fight each other: for example, a fix for a crashing bug must not be included if it breaks binary compatibility. like, sorry gorgeous, rules are rules 💅

okay also important: it is not necessary to include every single change that meets these criteria. in general the focus should be on addressing security issues, crashing bugs, regressions and serious installation issues. the temptation to sneak in a plethora of minor changes that don't affect the installation or execution of perl (e.g. spelling corrections in documentation)?? resist it. that's just asking to overlook something. the whole intention is to create maintenance releases which are both worthwhile and which users can have full confidence in the stability of. (a secondary concern is to avoid burning out the maint-release manager, or overwhelming the other committers voting on changes to be included — see "Getting changes into a maint branch" below.) 🫶

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:

  • Patches that fix CVEs or security issues. these changes should be passed using the security reporting mechanism rather than applied directly; see "SECURITY VULNERABILITY CONTACT INFORMATION" in perlsec. 🔐
  • Patches that fix crashing bugs, assertion failures and memory corruption but which do not otherwise change perl's functionality or negatively impact performance.
  • 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. yes queen, we respect the ancient upgraders 👑
  • Patches that fix bugs in features that were new in the corresponding 5.x.0 stable release.
  • Patches that fix anything which prevents or seriously impacts the build or installation of perl. 🛠️
  • Portability fixes, such as changes to Configure and the files in the hints/ folder.
  • Minimal patches that fix platform-specific test failures.
  • Documentation updates that correct factual errors, explain significant bugs or deficiencies in the current implementation, or fix broken markup.
  • 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. 🤝

The following types of change are NOT acceptable:

  • Patches that break binary compatibility. (please talk to the steering council.) 😬
  • Patches that add or remove features.
  • Patches that add new warnings or errors or deprecate features.
  • Ports of Perl to a new platform, architecture or OS release that involve changes to the implementation.
  • New versions of dual-life modules should NOT be imported into maint. those belong in the next stable series. 💀
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. lowkey that's the whole vibe check right there 💅

💖 Getting changes into a maint branch 💖

historically?? only the single-person project manager cherry-picked changes from bleadperl into maintperl. and bestie, that has scaling problems. meanwhile maintenance branches of stable versions of Perl need to be treated with great care. so to that end, as of Perl 5.12, we have a whole new process for maint branches ✨

Any committer may cherry-pick any commit from blead to a maint branch by first adding an entry to the relevant voting file in the maint-votes branch announcing the commit as a candidate for back-porting, and then waiting for at least two other committers to add their votes in support of this — i.e. a total of at least three votes is required before a commit may be back-ported. 🗳️ three votes, no cap.

Most of the work involved in both rounding up a suitable set of candidate commits and cherry-picking those for which three votes have been cast will be done by the maint branch release manager. but anyone else is free to add other proposals if they're keen to ensure certain fixes don't get overlooked, or if they fear they already have been. 🙈

Other voting mechanisms may also be used instead (e.g. sending mail to perl5-porters and at least two other committers responding to the list giving their assent), as long as the same number of votes is gathered in a transparent manner. specifically, proposals of which changes to cherry-pick must be visible to everyone on perl5-porters so that the views of everyone interested may be heard. no secret votes, we don't do that here 🎀

It is not necessary for voting to be held on cherry-picking perldelta entries associated with changes that have already been cherry-picked, nor for the maint-release manager to obtain votes on changes required by Porting/release_managers_guide.pod where such changes can be applied by the means of cherry-picking from blead. 🍓 so like, those ones are on the house.

💖 CONTRIBUTED MODULES 💖

🎨 A Social Contract about Artistic Control 🎨

okay bestie, this next bit is a whole statement about artistic control — which here means: the ability of a package's author to steer where their code goes and to keep a grip on their own work. It's a recognition that authors should have control over their work, and that the rest of the Perl community has a responsibility to make sure they keep it. It's an attempt to write down the standards we Perl devs intend to hold ourselves to, and to write down some rough guidelines about the respect we owe each other as Perl developers. 🫶

Real talk though — this statement is not a legal contract. It is not a legal document in any way, shape, or form. Perl ships under the GNU Public License and the Artistic License; those are the precise legal terms. This statement isn't about law or licenses at all. It's about community, mutual respect, trust, and good-faith cooperation. 💅

So: we recognize that the Perl core — meaning the software distributed with the heart of Perl itself — is a joint project on all our parts. Every so often, a script, module, or set of modules (from here on out just called a "module") proves so widely useful and/or so integral to Perl functioning correctly that it should be distributed with the core. This should never happen without the author's explicit consent, and with clear recognition on everybody's side that it means the module is now being distributed under the same terms as Perl itself. And a module author should know going in that inclusion in the core necessarily means some loss of control over it, since changes may occasionally have to be made on short notice or just for consistency with the rest of Perl. 😬

But once a module is in the Perl core, everyone involved in maintaining Perl should be aware that the module is still the property of the original author — unless that author explicitly gives up their ownership. Specifically:

  • 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. 💖
  • Patches may be applied by the steering council without the module author's explicit cooperation if and only if they are very minor, time-critical in some fashion (like urgent security fixes), or if the module author cannot be reached. Even then, those patches must still be given back to the author when possible, and if the author decides on an alternate fix in their version, that fix should be strongly preferred unless there's a serious problem with it. Any changes not endorsed by the author should be marked as such, and the contributor of the change acknowledged. 👑
  • The version of the module distributed with Perl should, whenever possible, be the latest version as distributed by the author (the latest non-beta version, in the case of public Perl releases) — though the steering council may hold off on upgrading the version shipped with Perl until that latest version has had sufficient testing.

In other words: the author of a module should be considered to have final say on modifications to their module whenever possible. (Bearing in mind that everyone involved is expected to work together and arrive at reasonable compromises when there are disagreements.) 🤝

As a last resort, though:

If the author's vision for their module's future is sufficiently different from the vision of the steering council and perl5-porters as a whole that it causes serious problems for Perl, the steering council may choose to formally fork the version of the module in the Perl core away from the one the author maintains. This shouldn't be done lightly, and should always — if at all possible — only be done after direct input from Larry. If it is done, it must then be made explicit in the module as distributed with the Perl core that it's a forked version and that, while it's based on the original author's work, it's no longer maintained by them. And this has to be noted in both the documentation and the comments in the source of the module. 📝

Again: last resort only, bestie. Ideally this never happens, and every possible effort at cooperation and compromise should be made before doing it. If forking a module really does prove necessary for the overall health of Perl, proper credit must be given to the original author in perpetuity, and the decision should be constantly re-evaluated to see whether the two branches can be remerged down the road.

In all dealings with contributed modules, everyone maintaining Perl should keep in mind that the code belongs to the original author, that they may not be on perl5-porters at any given time, and that a patch isn't official unless it's been integrated into the author's copy of the module. To help with this — and with points #1, #2, and #3 above — contact information for the authors of all contributed modules should be kept with the Perl distribution. 📇

And finally: the Perl community as a whole recognizes that respect for ownership of code, respect for artistic control, proper credit, and active effort to prevent unintentional code skew or communication gaps is vital to the health of the community and of Perl itself. Members of a community shouldn't normally have to resort to rules and laws to deal with each other, and this document — although it does contain rules so as to be clear — is really about an attitude and a general approach. The first step in any dispute should be open communication, respect for opposing views, and an attempt at compromise. In nearly every circumstance nothing more will be necessary, and certainly no more drastic measure should be used until every avenue of communication and discussion has failed. 🌸

📚 DOCUMENTATION 📚

Perl's documentation is a huge resource for our users, and it's incredibly important that it stays reasonably coherent and accurately reflects the current implementation. ✨

Just like P5P collectively maintains the codebase, we collectively maintain the documentation. Writing a particular bit of documentation doesn't give an author control over that documentation's future. At the same time — just like source code changes should match the style of the blocks around them — documentation changes should match their surroundings too.

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 are a snippet of code containing only the "important" bits. And what counts as "important" varies from snippet to snippet! Sometimes it's important to declare use strict and use warnings, initialize every variable, and fully catch every error condition. More often than not, though, doing all that obscures the lesson the example was meant to teach. 🎀

Since Perl is developed by a global team of volunteers, our docs often contain spellings that look funny to somebody. Choosing 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 rewriting the existing prose. 🌈

And in general: documentation should describe what Perl does now, not what it used to do. It's perfectly reasonable to include notes about how behaviour changed from previous releases, but — with very few exceptions — documentation isn't "dual-life", meaning it doesn't need to fully describe how all the old versions used to work.

🛡️ STANDARDS OF CONDUCT 🛡️

The official forum for perl development is the perl5-porters mailing list (mentioned above) and its bugtracker at GitHub. Posting to the list and the bugtracker is not a right: every participant in discussion is expected to adhere to a standard of conduct.

  • Always be civil. 🫶
  • Heed the moderators. 👑

Civility is simple: stick to the facts while avoiding demeaning remarks, belittling other individuals, sarcasm, or a presumption of bad faith. It is not enough to be factual. You must also be civil. Responding in kind to incivility is not acceptable. And if you relay otherwise-unposted comments to the list from a third party, you take responsibility for the content of those comments — so you must therefore ensure that they're civil. 💅

While civility is required, kindness is encouraged. If you have any doubt about whether you're being civil, just ask yourself, "Am I being kind?" and aspire to that. 💖

If the list moderators tell you that you're not being civil, carefully consider how your words have appeared before responding in any way. Were they kind? You may protest — but repeated protest in the face of a repeatedly reaffirmed decision is not acceptable. Repeatedly protesting the moderators' decisions regarding a third party is also unacceptable, as is continuing to initiate off-list contact with the moderators about their decisions.

Unacceptable behavior gets you a public and clearly identified warning. A second instance of unacceptable behavior from the same individual gets you removed from the mailing list and GitHub issue tracker for a period of one calendar month. The rationale? Giving the person an opportunity to change the way they act. 🙈

After the time-limited ban has been lifted, a third instance of unacceptable behavior results in a further public warning. A fourth or subsequent instance results in an indefinite ban. The rationale here is that, in the face of an apparent refusal to change behavior, we have to protect other community members from future unacceptable actions. That said, the moderators may choose to lift an indefinite ban if the person in question affirms they won't transgress again. 🌱

Removals, like warnings, are public. 📢

The list of moderators will be public knowledge. At present, it is: Karen Etheridge, Neil Bowers, Nicholas Clark, Ricardo Signes, Todd Rinaldo.

💜 CREDITS 💜

"Social Contract about Contributed Modules" originally by Russ Allbery <rra@stanford.edu> and the perl5-porters. 🫡

and that's the whole entire page, bestie, you ate it 💅✨ this was perl v5.44.0, dated 2026-10-17, and it lives at PERLPOLICY(1perl) — go be iconic out there 🦋💖

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