I often read opinions about using the best tool for the job in reference to choosing programming languages, frameworks, and libraries.
I am a polygot programmer but I am one mostly because I use languages and other software tools that my customers request. Seriously as a consultant I serve my customers' best interests and that process usually does not include trying to get their teams to pivot to use my favorite tools.
For my own side projects I am for the most part happy enough to use any of the languages that I feel most comfortable with, my favorites being Ruby and Clojure, but I also really like to use Java and Common Lisp. I usually choose languages for my own projects based on available frameworks and libraires that I can build my code on, and more rarely because of specific language features. Yes, I feel a little heretical saying that!
My secret for being comfortable with several languages is that I try to make the development experience similar across programming languages. For example, from the mid 1980s to several years ago I mostly lived inside Emacs. Certainly some language like Smalltalk carry their own IDEs around with them, but for the most part I used Emacs. Things are different now, I use various JetBrains IDEs because the editors, settings, etc. are all mostly similar:
- Clojure - I use IntelliJ with the La Clojure and Leiningen plugins
- Java - IntelliJ all the way
- Ruby - I use RubyMine most of the time with some quick work done in GEdit or TextMate
- Python - this is a tough language for me because I don't much use Python unless a customer is a Python shop. I find that PyCharm with code completion and instant syntax error hiliting really helps me a lot.
- Common Lisp - yes, I still use Emacs