Akka is a free and open-source toolkit and runtime simplifying the construction of concurrent and distributed applications on the JVM. Akka supports multiple programming models for concurrency, but it emphasizes actor-based concurrency, with inspiration drawn from Erlang.
Language bindings exist for both Java and Scala. Akka is written in Scala and, as of Scala 2.10, the actors in the Scala standard library are deprecated in favor of Akka.
Source: Wikipedia
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