Codeeval indicates that after Ruby and PHP, then Go, Haskell, Perl and Scala are the other most popular languages.
According to the ranking of popular languages at Tiobe, then Swift, F# and Dart are the most promising languages gaining popularity.
RedMonk ranking places JavaScript as the most popular language, with Clojure and Groovy rounding up the top 20.
The PyPL ranking has Lua as one of the promising one.
Vibes of a software writer 