Well, when I worked for Barclays Capital a few years ago, there was a lot of Perl ... mostly inherited from Lehman ... but how to make all those internal data import and massage programs into "verifiable, contactable references". The project I worked on was called ESM (Enterprise Security(or something) Master ... it was a system that imported data about securities from Bloomberg, stock exchanges, regulators and god only knows what other sources, merged and crosslinked them and provided the data to other internal systems. Part of that was Perl, part Java.