- security fixes
- indepence of /usr/bin/perl
- improved UNICODE support
- improved thread support
- misc. "minor" syntactical sugar (package Foo VER, __SUB__,
My €.1 about relying on stock /usr/bin/perl vs. latest and greatest:
It is true that vendor may choose to upgrade their perl in a way that is incompatible, and that this may hurt us.
But that will be true for anything installed on a box:
libc, libssl, openssh, bash.
The reason for incompatiblity may as well be due to some community/-ies changing policy/-ies
(like openssh vs. bash and the handling of .bash*).
And the incompatibility problem would certainly have hit us if we had choosen latest and greatest,
as 5.18.0 did move the given/when and ~~ into experimental mode
(and thus removing my best arguments...).
The only feasible way to handle this problem, is (at least in our case), automated testing of
our perl modules/scripts and all our other stuff, to ensure it works in the next new environment, whether it is new due to satellite server upgrades and/or a new version of latest and greatest.