© Springer Science+Business Media New York 2014. All rights are reserved. The success in Web services goes well beyond the building of loosely-coupled, interoperable software components. Nowadays, large-scale collaboration through social media (e.g., social networks) and new generation of serviceoriented software have spurred the growth of Web service ecosystems. This chapter discusses how a social ecosystem of Web services can be realized by defining first, the necessary actors that take part in this ecosystem formation and second, the interactions that occur between these actors during this ecosystem management. Such ecosystem permits to track who does what and where and when it is done. Compared to (regular) Web services, Web services in a social ecosystem take different actions that allow them, for instance to establish and maintain networks of contacts with other peers and to form with some peers strong and long lasting collaborative groups. The actors in the ecosystem are referred to as providers of Web services, providers of social networks of Web services, consumers of Web services, and providers of social networks of consumers. They all engage in different types of interactions like making Web services sign up in social networks of Web services, supporting users seek advices from existing members in a social network of consumers, and combining social networks of consumers and of Web services to achieve users' requests. Existing research initiatives on social Web services as well as open issues in the development of a social ecosystem of (social) Web services are also discussed in this chapter.