Scholarly communication is undergoing fundamental changes, in particular with new requirements for open access to research outputs, new forms of peer-review, and alternative methods for measuring impact. In parallel, technical developments, especially in communication and interface technologies facilitate bi-directional data exchange across related applications and systems. The aim of this roadmap is to identify important trends and their associated action points in order for the repository community to determine priorities for further investments in interoperability. A comprehensive list of interoperability issues has been created derived from a broad discussion in the information, publishing and repository community and each issue has been rated according to its level of complexity and temporal relevance (or timing).