CPAN::Meta::History − history of CPAN Meta Spec changes


version 2.150010


The CPAN Meta Spec has gone through several iterations. It was originally written in HTML and later revised into POD (though published in HTML generated from the POD ). Fields were added, removed or changed, sometimes by design and sometimes to reflect real-world usage after the fact.

This document reconstructs the history of the CPAN Meta Spec based on change logs, repository commit messages and the published HTML files. In some cases, particularly prior to version 1.2, the exact version when certain fields were introduced or changed is inconsistent between sources. When in doubt, the published HTML files for versions 1.0 to 1.4 as they existed when version 2 was developed are used as the definitive source.

Starting with version 2, the specification document is part of the CPAN-Meta distribution and will be published on CPAN as CPAN::Meta::Spec.

Going forward, specification version numbers will be integers and decimal portions will correspond to a release date for the CPAN::Meta library.


Version 2
April 2010

Revised spec examples as perl data structures rather than YAML

Switched to JSON serialization from YAML

Specified allowed version number formats

Replaced ’requires’, ’build_requires’, ’configure_requires’, ’recommends’ and ’conflicts’ with new ’prereqs’ data structure divided by phase (configure, build, test, runtime, etc.) and relationship (requires, recommends, suggests, conflicts)

Added support for ’develop’ phase for requirements for maintaining a list of authoring tools

Changed ’license’ to a list and revised the set of valid licenses

Made ’dynamic_config’ mandatory to reduce confusion

Changed ’resources’ subkey ’repository’ to a hash that clarifies repository type, url for browsing and url for checkout

Changed ’resources’ subkey ’bugtracker’ to a hash for either web or mailto resource

Changed specification of ’optional_features’:

Added formal specification and usage guide instead of just example

Changed to use new prereqs data structure instead of individual keys

Clarified intended use of ’author’ as generalized contact list

Added ’release_status’ field to indicate stable, testing or unstable status to provide hints to indexers

Added ’description’ field for a longer description of the distribution

Formalized use of "x_" or "X_" for all custom keys not listed in the official spec

Version 1.4
June 2008

Noted explicit support for ’perl’ in prerequisites

Added ’configure_requires’ prerequisite type

Changed ’optional_features’

Example corrected to show map of maps instead of list of maps (though descriptive text said ’map’ even in v1.3)

Removed ’requires_packages’, ’requires_os’ and ’excluded_os’ as valid subkeys

Version 1.3
November 2006

Added ’no_index’ subkey ’directory’ and removed ’dir’ to match actual usage in the wild

Added a ’repository’ subkey to ’resources’

Version 1.2
August 2005

Re-wrote and restructured spec in POD syntax

Changed ’name’ to be mandatory

Changed ’generated_by’ to be mandatory

Changed ’license’ to be mandatory

Added version range specifications for prerequisites

Added required ’abstract’ field

Added required ’author’ field

Added required ’meta−spec’ field to define ’version’ (and ’url’) of the CPAN Meta Spec used for metadata

Added ’provides’ field

Added ’no_index’ field and deprecated ’private’ field. ’no_index’ subkeys include ’file’, ’dir’, ’package’ and ’namespace’

Added ’keywords’ field

Added ’resources’ field with subkeys ’homepage’, ’license’, and ’bugtracker’

Added ’optional_features’ field as an alternate under ’recommends’. Includes ’description’, ’requires’, ’build_requires’, ’conflicts’, ’requires_packages’, ’requires_os’ and ’excluded_os’ as valid subkeys

Removed ’license_uri’ field

Version 1.1
May 2003

Changed ’version’ to be mandatory

Added ’private’ field

Added ’license_uri’ field

Version 1.0
March 2003

Original release (in HTML format only)

Included ’name’, ’version’, ’license’, ’distribution_type’, ’requires’, ’recommends’, ’build_requires’, ’conflicts’, ’dynamic_config’, ’generated_by’


David Golden <>

Ricardo Signes <>

Adam Kennedy <>


This software is copyright (c) 2010 by David Golden, Ricardo Signes, Adam Kennedy and Contributors.

This is free software; you can redistribute it and/or modify it under the same terms as the Perl 5 programming language system itself.