Ontology mapping is the process whereby two ontologies are semantically related at conceptual level and the source ontology instances are transformed into target ontology entities according to those semantic relations. The objective of MAFRA–MApping FRAmework – is to cover all the phases of the ontology mapping process, including analysis, specification, representation, execution and evolution. The MAFRA Toolkit is an implementation of MAFRA, adopting an open architecture in order to observe the Semantic Web requirements, namely performance and transformation capabilities. One of the MAFRA Toolkit novelties respects its service-oriented approach, which claims that the capabilities of an ontology mapping system dependent on what transformations are present. Independent, plug able services are then responsible for the instances transformations, but they also provide support for other ontology mapping tasks like automatic specification of semantic relations, negotiation and evolution...