&gt; I was hoping the JVM community would coalesce around one post-java language and I was hoping it was Scala. But now add Kotlin to the mix of Groovy and Clojure, and the future gets murkier<p>Those languages you mention each have vastly different use cases:<p>Scala = statically-typed replacement for Java, backed by Typesafe&#x2F;Lightbend, an FP&#x2F;OO hybrid by adding functional programming to the JVM<p>Kotlin = statically-typed replacement for Java, backed by Jetbrains, delivered via its popular IntelliJ product<p>Groovy = dynamically-typed addition to Java 7 and before, failed attempt to shift into static typing, no longer backed by any business, and no IDE plugin being maintained. Only used like bash for the JVM, and Gradle build files<p>Clojure = dynamically-typed addition to Java (all versions), backed by Cognitect, expanded to other platforms (e.g. ClojureScript, ClojureCLR)