Matchmaking should be understood, in a general way, as a search process for matchings between demand and supply requests within an application domain. This work defines a matchmaking software infrastructure whose domain instances are described in terms of an ontology. The proposed infrastructure has two major components: the framework Matching Module, which defines a flexible and extensible platform for dealing with matchmaking process, independently of the domain, and the OntoAPI, an API providing access services to semantically annotated data, that use RDF, RDFS or OWL as description languages.