The whole backend part (deployment and other scripts, business logic, web interface) is written in Perl.

Весь бэкенд (скрипты деплоя и прочие, бизнес-логика, веб-интерфейс) написан на Perl.

I use Perl to rip through log files and compare them to some signature files I have created. When I get a match, it adds the bad guy to the list of shame in MySQL.

A very expressive language, lets you say the same thing in many different ways

We use perl with rex to control our distributed systems.

NPL solutions and statistical machine learning.

As long as you don't abuse def and Closure

I use perl on some legacy applications.