[Skinney]

app, application, I wasn't thinking about mobile apps or the like.

I agree completely with using whatever I can be most successful with line of thinking. This is why I try to learn as many languages as I can, so I have a good notion of what is the best tool for the job.

Whenever I think "loads of concurrency" I immidietly think about Erlang, Clojure or Go, as they have great concurrency models. Then again, you'll always be more productive in the language in which you have most experience, so to each his own I guess :)