When Social Media and the Semantic Web became popular a few years ago it was a simple co-existence between the two, but in the meantime they have increasingly melted making it impossible to think of knowledge technologies without thinking of the Semantic Web. As we can witness today Social Media are widely accepted and common in educational, research and business contexts. Complementary to this Semantic Web principles have not only proven applicable at the technological level solving problems such as data integration and data quality management, but have also proved their applicability at the service level networking knowledge and people across diverse media, supporting search and retrieval, recommendation, collaboration and even trust and accountability issues, bringing Social Media to their full potential. The book at hand reflects on the increasing convergence of Social Media and Semantic Web technologies. It was the editors' intention to collect up-to-date and high quality contributions that illustrate various approaches to this young and emerging technology area.