Dear all, during next CLOSER conference there will be a special session dedicated to Cloud Interoperability: the topic is rapidly gaining momentum, and I considered as appropriate to find a place where to gather results and proposals, to have a snapshot of what's happening on the field. The members of this working group have an established interest and competence in the field, not restricted to the OCCI initiative. So I ask you some help for reviewing papers: if you are willing to spend some time evaluating the work of your colleagues, please let me know. Also pass the word to those that you think might volunteer for this fundamental contribution. This is also a call for papers: it would be desirable that the many groups and individuals that participate in the task of cloud interoperability find the time and resources to contribute to the event with a paper reporting their results. You find the details about the CLOSER conference at http://closer.scitevents.org/, and infos about the Cloud Interoperability session are at http://closer.scitevents.org/CI.aspx. The conference will be held in Aachen (Germany) 8-10 May, and the firm deadline for papers submission is *March 1st*. Thank you for your attention -- Augusto Ciuffoletti Dipartimento di Informatica Università di Pisa 56100 - Pisa (Italy)