Akka is a source-available platform, SDK, toolkit, and runtime simplifying building concurrent and distributed applications on the JVM, for example, agentic AI, microservices, edge/IoT, and streaming applications. Akka supports multiple programming models for concurrency and distribution, but it emphasizes actor-based concurrency, with inspiration drawn from Erlang.
Language bindings exist for both Java and Scala. Akka is mainly written in Scala.