It's just not suited for what I do. At work, I do number crunching. Essentially a bunch of simple calculations in a for loop. C++ is excellent for this. I use a

It's just not suited for what I do. At work, I do number crunching. Essentially a bunch of simple calculations in a for loop. C++ is excellent for this. I use a lot of Python for rapid prototyping, and as glue code. When I need to do concurrency, it's usually the easiest thing to run multiple instances in parallel, or to submit jobs to a cluster. There is already a well-tested infrastructure in place, and I don't need all the fancy stuff erlang has in this area. Second, but more important, my colleagues know C++ (good enough at least). If I started to use something else, we couldn't collaborate. We're physicists, not computer scientists or professional programmers. Then, I often find myself writing GUI code. I wouldn't know how to start writing a GUI in Erlang, but it's trivial in Python or C++. If anything, I would need a language centered around mutability, so almost the opposite of erlang. A language where everything is mutable, where you can databind to any object. Where you can just make an array of objects and bind it to a graphical widget, and get create, edit, update, delete operations for free. You never have to write `listview.insert(...)`. Maybe the command pattern is part of the language and it is trivial to write an undo function. And finally, it would include multithreading, with only a simple syncronization primitive, the transaction. The goal of concurrency here would not be speed, but GUI responsiveness. So, I have two very different use cases, for one I can use C++, for the other the ideal language has not been invented (but C# and Python are both not bad). I just don't know what to do with Erlang (and Haskell, Clojure, and all the other hip languages).