in reply to
How to answer "Perl is not secure" objections?
You have to distinguish between perl (the compiler/interpreter) and Perl (the language).
As for the program, I'd like to point you to the Common Vulnerabilities and Exposures List, search for Products -> Perl (don't enter 'perl' in the search box, it will find 'properly' as well).
Now compare these results to other interpreters and virtual maschines.
As for the language: you don't have to mess with your memory on your own (like C), you have tainting, no insecure register_globals (or whatever that stuff is called in PHP).