Stateflow
Developed by The MathWorks, Stateflow is a diagramming tool modelling event-driven systems that works with Simulink and MATLAB.
Stateflow is an interactive design and simulation tool for event-driven systems. Stateflow provides the language elements required to describe complex logic in a natural, readable, and understandable form. It is tightly integrated with MATLAB and Simulink, providing an efficient environment for designing embedded systems that contain control, supervisory, and mode logic.