Abstract: A number of existing Distributed Processing Environments (DPEs) are eligible to serve as a coordination architecture. In order to ease the construction of distributed applications while exploiting existing DPEs, the developer should be provided with notations that allow him to characterize the coordination architecture that is the best suited to his application. Existing DPEs can be distinguished according to at least two criteria:
i) the coordination protocols (e.g. RPC, pipe-filter, tuple space) they support, and
ii) the non-functional execution properties (e.g. availability, security, responsiveness) they provide.
This leads us to propose a twofold formal description of coordination architectures that characterizes the coordination protocols and non-functional execution properties that are expected from the underlying DPE, hence allowing to reason about the adequacy of a DPE for supporting a given coordination architecture.

Keywords: coordination protocols, coordination architecture, non-functional properties, software architecture, specification matching.