We use typesafe config for our Java configuration, after inheriting it via Akka + Play. The immutable recursive nature of the API is a slightly bigger win than

We use typesafe config for our Java configuration, after inheriting it via Akka + Play. The immutable recursive nature of the API is a slightly bigger win than the config itself, which is just OK. The way the config composes between reference.conf and application.conf and possibly more confs in the classpath can be a bit confusing, but the API gives you the ability to introspect the source of a config value. It's pretty nifty when you need the overlaying behaviour though. There's a lot more ports for it available now than when we started using it several years ago, which decreases its previously monolingual risk quite a bit.