I have a question -- why are you wanting to change the minimum? Is there something in particular that is broken? Or is there some specific benefit you are wanting that a later version provides?

I hear you are running on 5.16.0 now (might at least move to 5.16.3 and get some bug fixes if you stay at 5.16). Right now, among your customers, your "L.C.D." is 5.16.0 by virtue of the fact that you know that is working. Out of all your customers, one might assume some don't care (about software, or perl, whatever is on their computer, and only upgrade when they have to). The don't care contingent probably have whatever someone put on their machine(s) when they needed something.

So I guess I'm wondering what you are looking to achieve or what are you hoping to get as benefits by upgrading? It sorta sounds like you are thinking about upgrading just "cuz", but I am not sure. If your reasons for upgrading are to have a later-shinier perl, you need to balance that against what will be required to upgrade the "don't care" contingent from wherever they are at now (at least at 5.16.0).

Do your clients use the perl on their machines for anything else? I.e. if they run anything else that requires or uses perl will the other SW work seamlessly with a newer version? If you want to use a new feature of a newer perl, you need to balance that with the probability that such a feature may not be available in any version lower than the one you choose. I.e. if you use a perlI/O feature that allows you to write output to a string, you are locking yourself out of people using a default 5.6.x (likely not an issue, but an illustration of the point). In fact, if you use a specific feature, you might want to ensure it is still in the perl you switch to. Similarly, if you switch to a specific version to get a specific feature, you might want to see when it was introduced and what older versions might not be compatible.

If you haven't checked them out, you might want to peruse the perl5xxxdelta manpages/perldocs. At the very least, the 5160 5180, 5200 .. up through perl5320delta should show the main difference between the major releases. The minor releases like 5.16.1, 5.16.2, 5.16.3, theoretically are bug-fix releases and shouldn't create major changes, but that is in theory.

So in addition to just going with what is 'out there', you might want to ask why you are wanting to upgrade and ensure the new version meets your criteria while not dropping support for anything you are using now.

If any of the machines affected are directly on the internet (vs. some internal net) you might look at security probs in perl and if they might affect you, what version they were fixed in, but it sounded like you were talking about internal machines.

Anyway, I can't really say what version you should go with -- just make sure you need it and are going to get some definite benefits as a result of the switch.

On my network facing linux box, I'm still running 5.16 as well (though 5.16.3), though I do have up to 5.28.2 available on my system for testing. It's just that I know that any upgrade above 5.16.3 is very likely to bring some incompatibilities to some of my system scripts, and that's another headache I don't need right now. That said, most of my scripts and libraries also run on my desktop windows+cygwin environment where I have 5.26.0 installed, but perl isn't so critical on my windows box as it is on my linux box.

Good-luck!