[cbetti]

Yes. In the early 2000s Endeca made use of several public ontologies to enhance its information access and summarization products for clients.

One particularly compelling example that comes to mind was an ontology involving public companies, figures, events, and relationships that was combined with NLP (entity and concept identification) over semi-structured content on the ETL side, and faceted search and navigation on the retrieval side, to replace a research portal for a major UK newspaper in the mid 2000s. The results were mind blowing.