I feel most productive in Go. Less clutter to manage. Modern concurrency support. As for least productive, the Fallout 3 tool bench scripting language. Some pr

I feel most productive in Go. Less clutter to manage. Modern concurrency support. As for least productive, the Fallout 3 tool bench scripting language. Some proprietary nonsense with examples so bad they clearly didn't understand basic for loops. AppleScript is fairly awful, simply because it saves the source code as binary rather than text. newLISP has phenomenal API documentation, with at least one example for every function. Unfortunately not spec to either Scheme or CommonLisp. For spec, see Chicken Scheme.m or CLISP. Not a fan of Java, due to the temptation to overengineer everything. A second rate implementation of OOP in any case. altJVM languages tend to break the build tools. And you end up having to memorize two languages instead of one. I prefer compiled languages, but if I had to pick a dynamic one to save my life then that would be Ruby. My pseudocode mimics a mix of Ruby and other languages. Ruby gives you enough rope to hang yourself. Or build a bridge. It borrows IF as expression from Scheme. Shell (any flavor) has revealed just how risky the simplest line of code can be. The developer experience can be slightly improved here by turning on as many set safety flags as possible (e.g., set -eEuo pipefail). But generally I've learned to treat all shell scripts as time bombs. Just say no to ksh and to non-POSIX shell languages like Fish, PowerShell, rc, (t)csh. C++ as a teaching tool has been enlightening for studying applied computer science concepts, especially about performance. Rust has a smoother, less warty syntax. Python I would say is a siren calling out in sweet dulcet tones. As you approach production, Python snaps its eval jaws around your torso and drags you into the abyss. It looks friendly for newbies but is less reliable or expressive for advanced use. Ruby is similar but better in so many ways. Node.js has wonderful ideas with their NPM. Too bad about ECMAScript.