Erlang encourages this style through its OTP library; all of the default OTP behaviors include state machines as part of their operations, or make it so easy that they might as well. (gen_fsm is, as the name implies, a finite-state-machine, and it's trivial to use pattern matching to use a piece of the state in gen_event or gen_server to do the same thing). It doesn't sound like it has the full range of awesome that Ragel state charts do, but it has a lot of the value. It definitely gives you a lot of confidence that nobody can trick your server into doing something unexpected with weird input unless you do something very wrong yourself.