The data of different information systems is heterogeneous. As systems are being integrated, it’s necessary to bridge inconsistencies to reduce heterogenous data. To integrate heterogenous systems a mediator can be used. The mediator acts as a middle-layer for integrating systems, it handles transfers and translating of data between systems. A case study was conducted, developing a prototype of an integration mechanism for exchanging genealogical data, that used the mediator concept. Further, a genealogical system was developed to take use of the integration mechanism, integrating with a genealogy service. To test the reusability of the integration mechanism, a file import/export system and a system for exporting data from the genealogy service to a file was developed. The mechanism was based on the usage of a neutral entity model, that integrating systems could translate to. A neutralizing/de-neutralizing mechanism was used for the translating of the data between the neutral entity model, and a system specific entity model. The integration mechanism was added to the genealogy system as an addon. The integration mechanism was successful at integrating genealogy data. The outcomes included: The integration mechanism can be added as an addon to one or more systems being integrated. It was good to have a neutral entity model, together with a neutralizing/de-neutralizing mechanism.