An event engine enables application developers to define finite state machines (FSMs) that they want to implement, via a data-driven approach as opposed to having to hardcode the FSMs. The event engine has three notable characteristics: computations may be associated with FSM state transitions, the set of computations that is associated with each transition is specified by data (illustratively an XML document), and the particulars of the computations are defined and handled by plug-ins, each with the same interface.