There has been a flurry of Perl 5 releases over the last few days and there’s some evidence that this has confused a few people. So let’s take a closer look at what is available.

Perl 5.14.1
This is the most advanced stable version of Perl 5 currently available. It was released on 17th June. If you’re looking for the best version of Perl to use then this is the one to go for unless you have a good reason to choose one of the other versions mentioned below.

I’ve heard people mention the “stable Perl versions have an even number” rule as a possible reason not to use this version. They are wrong. That rule only applies to the middle integer in the Perl version number. Perl 5.10, 5.12 and 5.14 are stable versions. Perl 5.11, 5.13 and 5.15 are not. 5.14.1 is 5.14.0 with bug fixes. It is stable.

Perl 5.12.4
This version was released on 20th June. Due to a bug in CPAN, it currently shows as the most recent stable version of Perl. Well, maybe it’s not a bug as, strictly speaking, it is the most recent stable version of Perl. This version is a maintenance release on the 5.12.x branch. It fixes some bugs in version 5.12.3. Version 5.14.x is (obviously, I hope) a more advanced branch than 5.12.x. This release is intended for people who are tied to the 5.12.x branch for some reason. They get some bugs fixes but don’t have to switch to a whole new major version of Perl 5. Unless you’re tied to 5.12.x, you don’t need this version.

Perl 5.15.0
This version was released today (on 21st June). It is the first release in the 5.15.x development branch. This is the branch that will (in ten months or so) become Perl 5.16. The “stable Perl versions have an even number” rule applies to this version as the middle integer is 15. That’s an odd number. This is an unstable release.

That’s not to say you shouldn’t use this release. It has been released for a very good reason. The Perl 5 Porters would very much like you to download and try out this new version of Perl and report back to them with any problems that you see. But you shouldn’t consider putting it into production.

I hope that clear things up. If you’re wary of leaping to 5.14.x for some reason, then use 5.12.4. If you want a sneak preview of how Perl might look this time next year, then use 5.15.0. But most of you should be installing 5.14.1.