The Semantic Web is the second generation of the Web, which helps sharing and reusing data across application, enterprise, and community boundaries. Ontology defines a set of representational primitives with which a domain of knowledge is modeled. The main purpose of the Semantic Web and ontology is to integrate heterogeneous data and enable interoperability among disparate systems. Ontology has been used to model software engineering knowledge by denoting the artifacts that are designed or produced during the engineering process. The Semantic Web allows publishing reusable software engineering knowledge resources and providing services for searching and querying. This paper classifies the ontologies developed for software engineering, reviews the current efforts on applying the Semantic Web techniques on different software engineering aspects and presents the benefits of their applications. We also foresee other possible aspects where such techniques can contribute.