Erlang
Erlang's actor model is of particular interest, as are the constraint of immutable data and the error detection among processes. The ease of handling binary messages is a bonus. Though Scala also supplies the Actor model, it would be more motivating to learn about this high profile, battle tested solution. Erlang is used by many high profile companies, such as Amazon, Yahoo, Facebook, T-Mobile, Motorola, and, of course, EricssonAmazon, Yahoo, Facebook, T-Mobile, Motorola, and, of course, Ericsson.