Perl is an acronym Practical Extraction and Report Language. It started out as a simple way to massage data in text files and grew from there. Now it's highly regarded as a bit of a Swiss Army tool. It's available on the majority of Unix and Linux systems/distributions and there's almost no limit to the things you can do with it.

Sure, you can massage some data and report on it, but Perl does so much more than that. With the addition of a few Perl modules, you're able to write web applications, command line tools, system utilities, all sorts!

I've written web applications in Perl (although it was a while ago now, my current preference would be to do things in PHP) as well as numerous system utility scripts designed to make life just a little bit easier.