Perl 5.12 released; Perl 5 under new release process

By Jesse Vincent, thanks to Eric Brine and Shlomi Fish for the markup. Please note the section about the new time-based release process below.

‘Please would you tell me,’ said Alice, a little timidly, for
she was not quite sure whether it was good manners for her to speak
first, ‘why your cat grins like that?’

‘It’s a Cheshire cat,’ said the Duchess, ‘and that’s why.

She said the last word with such sudden violence that Alice
quite jumped; but she saw in another moment that it was addressed
to the baby, and not to her, so she took courage, and went on

‘I didn’t know that Cheshire cats always grinned; in fact, I
didn’t know that cats COULD grin.’

‘They all can,’ said the Duchess; ‘and most of ’em do.’

— Lewis Carroll, Alice’s Adventures in

On behalf of Perl’s development team, It gives me great pleasure
to announce the release of Perl 5.12.0.

Perl 5.12.0 represents approximately two years of development
since version 5.10.0 and contains over 750,000 lines of changes
across over 3,000 files from over 200 authors and committers.

SHA-1 signatures for this release:

f533687077e2da113b48a6c5e578f4a206fbf173  perl-5.12.0.tar.bz2
5341e60d099fdda71bc33b2a36e417fc0926518f  perl-5.12.0.tar.gz

You can download this release from your nearest CPAN mirror or

This release cycle marks a change to a time-based release
. Beginning with version 5.11.0, we make a new development
release of Perl available on the 20th of each month. Each spring,
we will release a new stable version of Perl. One month later, we
will make a minor update to deal with any issues discovered after
the initial “.0” release. Future releases in the stable series will
follow quarterly. In contrast to releases of Perl, maintenance
releases will contain fixes for issues discovered after the .0
release, but will not include new features or behavior.

Notable changes in Perl 5.12 include:

  • Perl now conforms much more closely to the Unicode standard.
    Additionally, this release includes an upgrade to version 5.2 of
    the standard.

  • New experimental APIs allow developers to extend Perl with
    “pluggable” keywords and syntax.

  • Perl now has a better sense of time and will be able to keep
    accurate time well past the “Y2038” barrier.

  • New syntax allows developers to specify package version numbers
    directly in “package” statements

  • Perl now warns the user about the use of deprecated features by

Perl 5.12.0 features numerous new features, optimizations and
bugfixes. You can find a complete list of these changes on the web

As specified in the licenses for Perl (see the files named
Artistic or Copying in the Perl distribution), THIS PACKAGE IS

Based on extensive testing over the past 3 months, we believe
that Perl 5.12.0 is ready for production deployments. However, you
should never blindly trust any software vendor. It is imperative
that you test new software before deploying it in production.

While we have worked tirelessly to ensure that Perl 5.12.0 will
be a solid platform for your software, it’s possible that issues
will be found after release day. You can find a current list of
known issues with Perl 5.12.0 at

Perl continues to flourish into its third decade thanks to a
vibrant community of users and developers. The following people are
known to have contributed the improvements that became Perl

Aaron Crane, Abe Timmerman, Abhijit Menon-Sen, Abigail, Adam
Russell, Adriano Ferreira, Ævar Arnfjörð Bjarmason, Alan Grover,
Alexandr Ciornii, Alex Davies, Alex Vandiver, Andreas Koenig,
Andrei Yelistratov, Andrew Rodland, Andy Armstrong, Andy Dougherty,
Jose Auguste-Etienne, Benjamin Smith, Ben Morrow, bharanee rathna,
Bo Borgerson, Bo Lindbergh, Brad Gilbert, Bram, Brendan O’Dea,
brian d foy, Charles Bailey, Chip Salzenberg, Chris ‘BinGOs’
Williams, Christoph Lamprecht, Chris Williams, chromatic, Claes
Jakobsson, Craig A. Berry, Dan Dascalescu, Daniel Frederick
Crisman, Daniel M. Quinlan, Dan Jacobson, Dan Kogai, Dave Rolsky,
David Cantrell, David Dick, David Golden, David Mitchell, David M.
Syzdek, David Nicol, David Wheeler, Dennis Kaarsemaker, Dintelmann,
Peter, Dominic Dunlop, Dr.Ruud, Duke Leto, Enrico Sorcinelli, Eric
Brine, Father Chrysostomos, Florian Ragwitz, Frank Wiegand, Gabor
Szabo, Gene Sullivan, Geoffrey T. Dairiki, George Greer, Gerard
Goossen, Gisle Aas, Goro Fuji, Graham Barr, Green, Paul, Hans
Dieter Pearcey, Harmen, H. Merijn Brand, Hugo van der Sanden, Ian
Goodacre, Igor Sutton, Ingo Weinhold, James Bence, James Mastros,
Jan Dubois, Jari Aalto, Jarkko Hietaniemi, Jay Hannah, Jerry
Hedden, Jesse Vincent, Jim Cromie, Jody Belka, John Malmberg, John
Peacock, John P. Linderman, John Wright, Josh ben Jore, Jos I.
Boumans, Karl Williamson, Kenichi Ishigaki, Ken Williams, Kevin
Brintnall, Kevin Ryde, Kurt Starsinic, Leon Brocard, Lubomir
Rintel, Luke Ross, Marcel Grünauer, Marcus Holland-Moritz, Mark
Jason Dominus, Marko Asplund, Martin Hasch, Mashrab Kuvatov, Matt
Kraai, Matt S Trout, Max Maischein, Michael Breen, Michael
Cartmell, Michael G Schwern, Michael Witten, Mike Giroux, Milosz
Tanski, Moritz Lenz, Nicholas Clark, Nick Cleaton, Niko Tyni, Offer
Kaye, Osvaldo Villalon, Paul Fenwick, Paul Gaborit, Paul Green,
Paul Johnson, Paul Marquess, Philip Hazel, Philippe Bruhat, Rafael
Garcia-Suarez, Rainer Tammer, Rajesh Mandalemula, Reini Urban,
Renée Bäcker, Ricardo Signes, Richard Foley, Rich Rauenzahn, Rick
Delaney, Risto Kankkunen, Robert May, Roberto C. Sanchez, Robin
Barker, Tomoyuki Sadahiro, Salvador Ortiz Garcia, Sam Vilain, Scott
Lanning, Sébastien Aperghis-Tramoni, Sérgio Durigan Júnior, Shlomi
Fish, Simon Schubert, Sisyphus, Slaven Rezic, Smylers, Steffen
Müller, Steffen Ullrich, Stepan Kasal, Steve Hay, Steven Schubiger,
Steve Peters, Tels, The Doctor, Tim Bunce, Tim Jenness, Todd
Rinaldo, Tom Christiansen, Tom Hukins, Tom Wyant, Tony Cook,
Torsten Schoenfeld, Tye McQueen, Vadim Konovalov, Vincent Pit, Hio
Yamashina, Yasuhiro Matsumoto, Yitzchak Scott-Thoennes, Yuval
Kogman, Yves Orton, Zefram and Zsban Ambrus.

This list is woefully incomplete as it’s automatically generated
from version control history. In particular, it doesn’t include the
names of the (very much appreciated) contributors who reported
issues in previous versions of Perl that helped make Perl 5.12.0
better. For a more complete list of all of Perl’s historical
contributors, please see the AUTHORS file in the Perl 5.12.0


Jesse Vincent

What are you working on in Perl?

My project list is a mile long, and I’m wondering what you’re working on, too.
Here’s mine, in no order:
* Internals of [Parrot](, trying to get the underlying C API handle to handle const STRING *.
* Putting out [tidyp](, my fork of libtidy, and HTML::Tidy which will rely on it.
* Thinking about the plug-in API for [ack]( 2.0.
* Wanting to get more grep-like programs listed on [](
* Gathering together info on Plack and PSGI for an article here
* Getting []( to list both Perl 5 and Perl 6 syntax for how to do things.
* Make an install mechanism for [vim-perl]( so people don’t have to wait for Bram to release a version of vim to get the updates.
* Work on [Perl::Critic]( policies for [](
* Clean out the WWW::Mechanize bug queue, especially making the live tests not run by default.
* Work on a talk on Perl 5.10 and 5.12 for [Chicago Uniforum]( in June.
* Add more languages and more philosophy to [](
* Decide if I want to keep Perlbuzz in Movable Type and upgrade to the next version, or migrate to the Melody fork.
What’s on your plate? Tell us in the comments.

White House releases open source code

I’m so happy that the [White House has fed back to the open source community]( and, more importantly, advertised that fact.
Remember how fifteen or twenty years ago you’d see mentions of the Internet in popular culture and think “This is really picking up”? That’s how this announcement makes me feel.

Perlbuzz news roundup for 2010-04-22

These links are collected from the
Perlbuzz Twitter feed.
If you have suggestions for news bits, please mail me at

Perlbuzz news roundup for 2010-04-05

These links are collected from the
Perlbuzz Twitter feed.
If you have suggestions for news bits, please mail me at