RedSteak - a clonable, mutable UML 2 StateMachine for Ruby.

Features:

• Implements UML 2.1 StateMachines (partially).
• StateMachines can be instantiated then cloned via StateMachine#copy.
• Submachines are supported, a state may have an imbedded StateMachine.
• Builder DSL simplifies construction of complex statemachines.
• StateMachines can be serialized.
• StateMachines can be modified on-the-fly.
• Context objects can be notfied of transitions, enter and exit actions.
• Context objects can be used to create transition guards.
• StateMachines, States and Transitions are objects that can be extended with metadata.
• History of transitions can be kept.
• Multiple machines can execute the same statemachine without side-effects.
• StateMachines and their transition history can be rendered as Dot syntax.