The 2nd Social Data on the Web workshop3 (SDoW2009) co-located with the 8th International Semantic Web Conference4 (ISWC2009) aims to bring together researchers, developers and practitioners involved in semantically-enhancing social media websites, as well as academics researching more formal aspect of these interactions between the Semantic Web and Social Web.

Since its first steps in 2001, many research issues have been tackled by the Semantic Web community such as data formalism for knowledge representation, data querying and scalability, or reasoning and inferencing. More recently, Web 2.0 offered new perspectives regarding information sharing, annotation, and social networking on the Web. It opens new research areas for the Semantic Web which has an important role to play to lead to the emergence of a Social Semantic Web that should provide novel services to end-users, combining the best of both Semantic Web and Web 2.0 worlds. To achieve this goal, various tasks and features are needed from data modeling and lightweight ontologies, to knowledge and social networks portability as well as ways to interlink data between Social Media websites, leveraging proprietary data silos to a Giant Global Graph.

Following the successful SDoW2008 workshop at ISWC20085 , SDoW2009 aims to bring together Semantic Web experts and Web 2.0 practitioners and users to discuss the application of semantic technologies to data from the Social Web. In this edition 12 papers have been finally accepted from a total of 23 submissions.

The workshop organization would like to thank all people involved in the workshop, specially to the authors and to the members of program committee.