DaWaII (Data Warehouse IntegratIon) is a tool supporting the various activities related to the integration of multidimensional data. This problem arises in common scenarios where there is the need to combine independently developed data warehouses. Actually, a today common practice for building a data warehouse is to develop a collection of integrated data marts, each of which provide a dimensional view of a single business process. These data marts should be based on shared dimensions but very often, even within the same company, designers develop their data marts independently and it turns out that their integration is a difficult task. Indeed, the problem arises in other common cases. For instance, when different companies get involved in a federated project or when there is the need to combine a proprietary data warehouse with external information, for instance, with multidimensional data wrapped from the Web.