By implementing this interface and placing the DLL containing the implemented class in bin, 3ds Max will, as a result, dynamically load an instance of this class as an action in its CUI interface.
When the action is executed, it will call ICommand.Execute().
A client only need to satisfy the ICuiActionCommand interface for their class to be loaded by the managed assembly loading process. However, The CuiActionCommandAdapter class exists to make this interface easier to use.