As a result of the global interconnectivity ensured by the Web, the new landscape of systems that are operating in cyber-space is that of networks of systems where execution at the network nodes, which could be triggered by humans or performed by programmed devices, enable the spontaneous evolution of network links: as they execute, applications create a ‘social network’ of their own and use it to procure the resources or services that they need to fulfil their own ‘selfish’ goals. In this talk, we discuss a component and an interface algebra (in the sense of de Alfaro and Henzinger) for such dynamic networks of interactions. The component algebra allows us to reason about global properties of such networks such as consistency (all the processes in the network can agree on a joint trace) and what we call "dynamic consistency" (all the processes in the network can agree on a joint trace no matter what interactions the network receives from its environment). The interface algebra gives us the means to control the way a network can evolve by restricting the interconnections that it can establish with other networks. This is joint work with Antónia Lopes, Faculdade de Ciências da Universidade de Lisboa.
João Paulo Marques da Silva