The say feature was introduced in Perl version 5.10. In order not to break programs written under older versions which might for example use a say function for something else, the say features requires a use pragma such as use 5.10 or use 5.14. This way, older programs continue to work properly, but you can use say in new programs through the use pragma.

As for versions, 5.14.2 and 5.014002 are just the same, two differents notations for the same version.