Choosing a language for a project rarely comes down to researching the languages that may best deal with the problem. More often than not from my experience, it’s what the first engineer(s) on the project thought would be fun (annoyingly often in the case of using new languages in production), were most-familiar in, or the company is most familiar with, or because some library they need to use is only available in X language and it would take too long to do the project and implement the library in their “normal” language.

Perl, Python, and Ruby are all pretty competent and on the same level. Given that Perl is chosen as a language the question isn’t “Justify the use of Perl to the exclusion of Python and Ruby.” It’s “What can Python or Ruby do that Perl can’t?”

Some common arguments between Python and Perl can be found at http://coosoft.wordpress.com/2013/02/24/the-perl-vs-python-d... (I would add the author should have expanded on Object Oriented in Perl more. While native OO in Perl is exceptionally basic, third party OO frameworks for the language exist such as Moose and Moo complete with introspection, roles, type constraint, triggers, attributes, etc, etc).

Perl is a powerful modern language, actively developed by a committed community[1]. We’re just generally too busy doing things to blog about all the awesome stuff as much, so people’s perceptions of the language are often stuck in 1998.

[1] https://www.youtube.com/watch?feature=player_detailpage&v=hH...

Their OO is terrible. Especially ruby's (single inheritance and a half-ass mixin system ... yeah, right).

Perl5's built-in OO is even more terrible, but exposed enough guts for Moo/Moose to be written, which is far, far superior.

Note that there's a MooseX rubygem and an Elk python package, because apparently there are people actively using ruby and python who also miss sensible OO :)

(I can elaborate on what I find superior but you might find it more instructive to see what people have ported than what I miss)

I personally also use Python regularly and am very comfortable with it, but we often choose Perl because of the developer experience in it.

Perl has a reputation for being difficult to learn, and it does have a bit of a high learning curve compared to Python. However, once you learn Perl, you'll find it's a rather wonderful, expressive. and powerful language.

Is it "better" than Python or Ruby? No, just a different solution to many of the same problems. If we're being honest, most anything you can do in Ruby or Python can also be done in Perl.

My experience is that most engineers and devs over the age of ~30 know Perl front and back (if they script), so it's a natural choice. Fewer of these people (in my experience) are as familiar with Python/Ruby.

Perl continues to evolve and the Perl we wrote in 1998 isn't the same as the "Modern Perl" we write in 2014. There are great modern Perl web frameworks (Dancer, Mojolicious), real object-orientation via Moose, powerful exception handling via Try::Tiny, and a history of excellent database support.