The Chemical Reaction Model Recent Developments and Prospects

In 2001, we gave a survey of more than fifteen years of research on the chemical paradigm which had been a source of inspiration in many different research areas. The present article presents a digest of recent advances concerning the chemical reaction model. We focus to a large extent on: (1) upgrading the basic model to a higher order formalism allowing reactions to be part of solutions and to take part in reactions and (2) generalizing standard multisets to hybrid and infinite multisets, thus providing new forms of interactions between elements. These novelties, incorporated in the HOCL language (High Order Chemical Language), provide natural and elegant ways of expressing properties related to coordination and self-organization of systems. Finally, we present current research directions which strive to make the chemical reaction model effective particularly in the programming of large-scale, highly parallel applications such as Grids.