This paper summarizes the results of the X-SOM tool in the OAEI 2007 campaign. X-SOM is an extensible ontology mapper that combines various matching algorithms by means of a feed-forward neural network. X-SOM exploits logical reasoning and local heuristics to improve the quality of mappings while guaranteeing their consistency. 1 Presentation of the system Nowadays, the spreading of data intensive and community-centered web-applications has multiplied the number of available datasources accessible through the Internet. In order to effectively query and integrate this information, a shared formalism should be used, at least as a means to mediate the access to datasources. In many situations, ontologies [8] have demonstrated , to be a suitable formalism for evenly representing the content of heterogeneous datasources [15], with a well-defined semantics. In principle, it is possible to extract an ontology from a datasource, and then integrate its information content with that of other da...