Today's consumers have a wide variety of interactive media and services at their disposal, for instance, through IPTV networks, the Internet, and in-home and mobile networks. A major problem, however, is that media and services do not interoperate across networks because they use different user identities, metadata formats, and signaling protocols, for example. As a result, users cannot easily combine media and services from different network infrastructures and share them in an integrated manner with their family and friends. In addition to limiting people's media experience, this also hinders the introduction of new services and business models as providers cannot easily develop and operate cross-network services. The goal of our work is to overcome this problem by means of an open and intelligent service platform that allows applications to easily combine media and services from different network infrastructures, and enables consumers to easily share them in an integrated way. The platform includes support for managing multi-user sessions across networks, context-aware recommendations, and cross-network identity management. While there has been prior work on platforms for converged media, our platform is unique in that it provides open, intelligent, and interoperable facilities for sharing media and services across network infrastructures. In addition, our work involves several specific innovations, for instance, pertaining to cross-network session management and synchronization. In this article we discuss the platform, its most important enabling services, and some of the applications we have built on top of it. We also briefly consider the new kinds of business models our platform makes possible