In previous work [1] we presented a framework for the speci- fication of open computational societies i.e. societies where the behaviour of the members and their interactions cannot be predicted in advance. We viewed computational systems from an external perspective, with a focus on the institutional and the social aspects of these systems. The social constraints and roles of the open societies were specified with the use of the Event Calculus. In this paper, we formalise our framework with the use of the C+ language, a formalism with explicit state transition semantics. We use the implementation of the C+ language, the Causal Calculator, a software tool for representing commonsense knowledge about action and change, to animate and validate the speci fications of computational societies. We demonstrate the utility of the Causal Calculator (by specifying and executing a Contract-Net Protocol) and comment on its functionality regarding the specification of computational societies.