what are some of the things that you wouldn't use perl for?

This is a question that intrigues me. Why? Because I quite often do one of two things:

1. Prototype a project in Perl and then port it to some other language such as C or C++
2. Occasionally start out writing an application in some other language and end up writing it in Perl.

I probably would not use Perl to write a device driver for *nix or *doze. I might however write an interface using XS against a C API to drive the resultant device.

I might not use Perl to do real time data aquisition but I would probably post process the results in Perl to make it presentable.

So while I could think of things that I wouldn't do directly in Perl there are way too many other uses I do have for the language. I don't remember a project in the last 10 years that I haven't resorted to Perl at some point. Even one of my current projects where I am rewriting the startup scripts for a vendor application I am invoking a Perl script from a bash shell script put in /etc/init.d and linked appropriately.

Not for closed source applications? More correctly I won't use Perl for the odd occasion where I write something that I don't want a casual user to see the "naughty bits" of what is going on behind the scenes.