Also, PSGI/Plack might be contra-indicated depending on exactly how your application is now architected.

Rubbish. Unless there are scoping problems—which is essentially broken code and requires one to eschew strict—there is no reason to avoid persistent execution harnesses, fcgi, or psgi.

I'm going to defend sundial's point just a little bit here. Given that the shortest path to keeping this code working is to install CGI.pm manually, there's no urgent reason to migrate to a PSGI system.

Also I think you're overstating the value of strict in this case; it's easy to write a simple and correct and strict-safe CGI program that causes inadvertent scope problems with a persistent execution harness like mod_perl. (Plack less so.)

Then I'm going after yours. *I* wrote, without PSGI qualification, Just install CGI.pm at the most recent version that will run your code on your new server and I did it five and half hours before the artist formerly known as Coat-tails McGee. It's guaranteed that if you ask him what architecture concerns make PSGI a non-starter, he will not answer. He doesn't know.