For integration and use of commercial and open source tools, libraries and components, I wonder if Perl or Python is easier or more superior. I wonder if Perl's CPAN has something that Python doesn't and thus a better choice.
If my understanding is correct, most commercial software do not have SDK for Perl or Python. Open source libraries tend to be in Java.
Of course syntax wise, Perl is good for writing less lines and achieving more results, since Python is strict with its formatting and indentation. If one needs a short script to do quick hack, it would be easier to do with Perl.
Just my observation.
I must say Perl has been around for nearly as long as Python, knowing that Perl was just 4 years ahead of Python, but I must say having my first encounter with programming back in year 2000, Perl is very popular and Python didn't even register in my radar. Apparently as I read
http://www.fastcompany.com/3026446/the-fall-of-perl-the-webs-most-promising-language, it's agreeable if you started out with Perl and your learn its ways, you work better with it and it still does it job well in the way you want it to, then carry on. If you knows Python or you started out with Python and you find it makes your life easier, go with it.
I don't think Opensource libraries are tend to be for Java, there are open sources for numerous other languages and having CPAN has been there for a long time, everything there are open source. Java and .NET excel in a different industry setting as oppose to Perl and Python, so I don't think you really want to compare them side by side. The kind of developers and projects that they serve can be somewhat different in nature.
The superiority of programming languages is always a running target. Soon another language will take over Java and then you will find more recent topics and libraries built with those programming languages as long as they can reach out to more developers and more developers are developing in those languages.
What's really important is learning how to interoperate between multiple languages and platforms. There are cross platform interfaces like SOAP/XML/JSON/HTTP/RMI and other approaches to make platforms of different make and model working together. You don't have to force fit to whichever is superior.