Perl is an efficient programming language which is widely used for generating CGI scripts as well as various web-based apps. One of its major advantages is that it works with modules - ready-made batches of code which are designed to execute a variety of tasks and to extend the effectiveness of a given script without slowing it with unneeded lines of code. In other words, if five tasks need to be executed, you're able to employ five lines of code to call each of the modules instead of adding a few hundred lines used to create the actual modules within your script. Perl is really practical and it may be used for many different purposes, so a number of companies have included it in their web products or on their high-traffic sites - cPanel, IMDB, Craigslist, BugZilla, BBC and many more. It's commonly used with other programming languages like PHP or Python.