Until recently, Python and Ruby were ahead of Perl when it came to developing web applications. Now, thanks to the work of the plackists, we’re right back up there again. By the time I could have become proficient Python + WSGI, Plack and PSGI will be equally good, or better.
So, yeah, when it comes to libraries, we are the champions. Okay, there might be a couple of utilities like Rake and Capistrano that haven’t been duplicated yet, but I’m sure someone is working on it1.
However, there is a reason why you might want to use Python or Ruby ahead of Perl. And that is Google App Engine and heroku. If you have an idea for a web app, you can get started for $0. I know about perl-appengine but it seems to be moribund.
With Perl, if shared hosting is enough for you, a half-decent plan costs $6/month which is $72/year. More likely, you would want a VPS so you can install Plack and Starman which will cost closer to $20 – $25 / month or $240 – $300 / year.
Okay, so it isn’t a reason why I personally would use Python or Ruby over Perl – my free time is somewhat valuable to me. But if you’re getting started and you’re not sure which of the big three scripting languages to choose, it is a strike against Perl.
1. And if they’re not, I don’t need ’em anyway