There are a number of ways of simulating and executing various aspects of Systems Modeling Language (SysML®), and they are not just novelties! They also really help your models become more robust, logical, and organised.
There is "internal" tool simulation of Activities and StateMachines based on fUML (or variations of it).
Alf - the Action Language for Foundation UML - is a UML-friendly textual "surface language" intended for use together with fUML. Useful for those tasks in Activity and StateMachine diagrams that don't lend themselves to graphical modelling.