Ontology Repositories

The growing use and application of ontologies in the last years has led to an increased interest of researchers and practitioners in the development of ontologies, either from scratch or by reusing existing ones. Reusing existing ontologies instead of creating new ones from scratch has many benefits: It lowers the time and cost of development, avoids duplicate efforts, ensures interoperability, etc. In fact, ontology reuse is one of the key enablers for the realization of the Semantic Web. However, currently, ontologies are mostly developed from scratch, due to several reasons. First, ontologies are usually tailored to work for specific applications, restricting its potential reusability. Second, developers usually follow a monolithic approach when developing ontologies, usually covering different domains, hampering the reusability of relevant parts for other applications. Third, ontologies are rather difficult to find due to the lack of standards for documenting them and appropriate tools supporting intelligent ontology discovery and selection by end users. In this chapter, we define a generic ontology repository framework that enables the implementation of fully-fledged ontology repositories providing the technological support to the aforementioned issues. We distinguish between the ontology repository itself and the software to manage the repository, and describe their main aspects and services. Finally, we present two exemplary systems based on this framework.