IMHO: Scala by far - You can use pretty much any JVM library - You can execute Scala applications in a JVM which is a pretty common platform for other tools.

IMHO: Scala by far - You can use pretty much any JVM library - You can execute Scala applications in a JVM which is a pretty common platform for other tools. Think CI, deployment on servers, etc. - Akka Cluster out of the box. On other systems you have to build your custom communication pipelines for messaging between your multiple instances of the services