State machine processor reference implementation?

I&#x27;m rewriting a state machine processor for a system at my company. The primary goal is to implement declarative JSON based language for describing state machines so that we have a higher level way of thinking than the current, purely-java solution. The second, more challenging goal is to abstract the components of the system such that the initial implementation can be single node, but getting enough of the correct interface definitions such that it could be refactored to support distributed execution and fault tolerance.<p>Since I&#x27;ve not written one of these before, I&#x27;m rooting around the web looking for reference implementations &#x2F; papers &#x2F; boxes-and-arrows that could provide inspiration. Any thoughts on what to read?