International audienceThe digital creative industries exemplify innovation processes in which user communities are highly involved in product and service development, bringing new ideas, and developing tools for new product uses and environments. We explore the role of user communities in such co-innovation processes via four case studies of interrelations between firms and their communities. The digitization and virtualization of firm/community interactions are changing how boundaries are defined and how co-innovation is managed. The transformation of innovation management is characterized by three elements: opening and redefining firm boundaries; opening of products and services to community input and reducing property rights; and reshapi...