Towards An Open And Heterogeneous Social Web

Online Social Networks (OSN) have become an integral part of our everyday lives. We express ourselves, share content and information with our friends and colleagues, or exchange messages. Yet, despite social communication being implicitly a distributed, decentralized way of information exchange that does not require any central entity to supervise the process, most OSN services are built in a central, monolithic fashion. This contradicts the idea of the social web, as proprietary and isolated walled gardens keep users from being able to freely choose an OSN platform provider or to effectively control their privacy. To enable users of the social web to remain in control of their social profiles and data, solutions were proposed that allow hosting one's social profile on independent servers, which then connect to each other in a loosely coupled fashion. Unfortunately, implicit network effects existing in large OSN services prevent users from migrating to alternative solutions thus ultimately hindering alternative OSN services to succeed in the social web. In this paper, we outline the main challenges that need to be addressed in order to allow decentralized OSN services to become real alternatives to well-established services such as Facebook or Twitter. The identified main challenges are coverage of typical, standard OSN functionality, a holistic and extensible interoperability protocol, support for data portability of entire social profiles, and support for platform-independent user identification. The paper then outlines Sonic, an open architecture for an open and heterogeneous network of independent OSN services, the Online Social Network Federation (OSNF), in which the identified challenges are addressed altogether.