In a distributed system, shared data is replicated. Updates cause replicas to diverge. Reconciliation repairs the divergence. IceCube is a general-purpose reconciliation engine, parameterised by the semantics of shared data and by the users' declared intentions. Refer to: http://research.microsoft.com/scripts/pubs/view.asp?TR_ID=MSR-TR-2002-52, Efficient semantics-aware reconciliation for optimistic write sharing, by Nuno Preguiça, Marc Shapiro and Caroline Matheson.