Towards the theoretical foundation of choreography

With the growth of interest on the web services, people pay increasingly attention to the choreography, that is, to describe collaborations of participants in accomplishing a common business goal from a global viewpoint. In this pa-per, based on a simple choreography language and a role-oriented process language, we study some fundamental is-sues related to choreography, especially those related to im-plementation, including semantics, projection and natural projection, dominant role in choices and iterations, etc. We propose the concept of dominant role and some novel lan-guages structures related to it. The study reveals some clues about the language, the semantics, the specification and the implementation of choreography