I'm slightly surprised that nobody (as far as I've seen) have mentioned SDL: https://en.wikipedia.org/wiki/Specification_and_Description_Language https://en.wik

I'm slightly surprised that nobody (as far as I've seen) have mentioned SDL: https://en.wikipedia.org/wiki/Specification_and_Description_Language https://en.wikipedia.org/wiki/Specification_and_Description_... SDL is widely used in telecom and datacom systems to develop the control plane. Most tools are of the draw your code-type, which ends up being a unmanagable mess in direct contrast to what management thinks. But the tools will generate state machines that pass messages between eachother and to controlling interfaces based on states an inputs. The point being made for SDL is that you can easily simulate the whole system and watch/test that the control plane will work as intended before the HW has been built.