Erlang was developed by Erikson almost 30 years ago. Its claim to fame is reliabilty. 99.9999999% uptime. Unbelievable. An individual CSP process may fail, but the whole system continues running.
Erlang is a Functional Programming Language. State is never mutated. I believe the reason for this design decisin, is that it reduces hidden bugs. The code becomes more readable and understandable.