Statecharts in the making: a personal account

This paper is a highly personal and subjective account of how the language of statecharts came into being. The main novelty of the language is in being a fully executable visual formalism intended for capturing the behavior of complex real-world systems, and an interesting aspect of its history is that it illustrates the advantages of theoreticians venturing out into the trenches of the real world, "dirtying their hands" and working closely with the system's engineers. The story is told in a way that puts statecharts into perspective and discusses the role of the language in the emergence of broader concepts, such as visual formalisms in general, reactive systems, model-driven development, model executability and code generation.