Book of Abstracts: Cloud Services for Synchronization and Sharing 30 January - 1 February 2017, SURFsara Amsterdam, The Netherlands It has become progressively clearer that services capable to synchronise, share and interact with growing data volumes could become the keystone of new ways to do research. Early prototypes of innovative non-traditional working storage exist: systems having at their centre synchronisation and sharing capabilities are natural candidates to host demanding data processing in the future. Large-scale synchronization and sharing capabilities are already challenging existing IT infrastructures in all areas, from security models to integration with compute resources. This situation calls for renewing computing infrastructures and the way research is done locally and across collaborating institutes. We will meet at the 3rd Cloud Services for Synchronisation and Sharing (CS3) Conference to review the state-of-the-art and share experiences about cloud storage services. The community which gathered around the previous CS3 events includes users, service providers and developers of technological solutions. As in the past, the conference will maximise the opportunity to liaise with key actors of the community. In the previous CS3 conferences we witnessed the grow in complexity of Cloud Storage installations along the maturing of related technologies. Key actors in the Cloud Storage met at CS3 bridging between the evolution of technologies (and the need to standardise and interoperate) with new ideas from user communities exposing their experience and needs. Three facts became clear during last conference at the ETH in Zurich: Existence of a vital community convinced on the potential of Cloud Storage technologies Demonstration of Cloud Storage as new platform for scientific and technical research Need of a Cloud Storage federation to enable collaborative research across different institutes and infrastructures An hallmark of CS3 has always been to invite companies and development teams to share their experience and plans: they are invited to submit abstracts about their strategy and their technologies to be openly discussed. We have seen that this is important in complementing the experience and plans from groups providing Cloud services and users comparing and proposing new ways to use these services. Topics of interest: Innovative user applications and workflows with cloud storage services Protocols and semantics for file sharing and synchronization Consistency and scalability of file synchronization services Backend storage technologies Federated access to cloud storage Programme Committee Guido Aben (AARNet) Massimo Lamanna (CERN) Luca Mascetti (CERN) Jakub T. Moscicki (CERN) Tilo Steiger (ETH) Ron Trompert (SURFsara) Editor of the Book of Abstracts Belinda Chan (CERN)