Abstract. Ontology matching consists of finding correspondences between ontology entities. OAEI campaigns aim at comparing ontology matching systems on precisely defined test sets. Test sets can use ontologies of different nature (from expressive OWL ontologies to simple directories) and use different modalities (e.g., blind evaluation, open evaluation, consensus). OAEI-2007 builds over previous campaigns by having 4 tracks with 7 test sets followed by 18 participants. This is a major increase in the number of participants compared to the previous years. Moreover, the evaluation results demonstrate that more participants are at the forefront. The final and official results of the campaign are those published on the OAEI web site.