Nowadays, most of the information exchanged in Internet (particularly through social networks) is in the form of multimedia data. Each actor in Internet (individuals, enterprises, territorial communities, etc.) becomes producer and consumer of contents. Development and increasing demand for multimedia data offer producers/consumers more choices and opportunities for sharing in collaborative environments. Nevertheless, social network platforms and other traditional collaborative environments present limitations regarding content selection and collection, categorization and classification, aggregation, linking and interoperability, usage control and privacy. In this context, this ongoing work proposes a MultiMedia-Oriented Digital EcoSystem (MMDES) as a new environment of collaboration, sharing, and computing of multimedia content and applications ensuring the benefits of all its participants. In this paper, we formally define MMDES components, objectives and rules through a dedicated ontology. We also present here a P2P architectural design for MMDES.