I'm a database/middleware developer by trade.
My RDBMS platform of choice is MS SQL Server. Really.
That unfortunately means that my OS is NT. D'oh.
Perl is useful on *nix systems, but it's absolutely essential on NT. You can't live with out it.
I used to prototype my COM objects in perl and replace it with C++. Now I roll the perl directly into production. No one has noticed a performance problem, and I'm coding 3 times as fast.
I love perl.