I would also look outside of the JVM box and consider C#. It stays familiar, while having proper parallelism and concurrency constructs: async+await, TPL, TPL D

I would also look outside of the JVM box and consider C#. It stays familiar, while having proper parallelism and concurrency constructs: async+await, TPL, TPL DataFlow, Parallel. Alternatively there is also F# with it's Erlang-inspired http://en.wikibooks.org/wiki/F_Sharp_Programming/MailboxProcessor http://en.wikibooks.org/wiki/F_Sharp_Programming/MailboxProc...