Perl releases are identified by a version number, a sequence of at least two numbers, separated by periods. This books describes Perl 5.14.1, released on June 16, 2011.
The language revision. Perl 5 was first released on October 17,1994.
The version of this revision.
An even number indicates an official production version, while an odd number indicates a development version.
The subversion. 0 (zero) is the first release, higher numbers indicate maintenance releases.