Google Refine is a power tool for cleaning up raw data, making it consistent, linking it to data registries like Freebase, augmenting it with more data from other data sources, transforming it into the required format for other tools to consume, and contributing it back to some data sources like Freebase. Google Refine is not a web service but a desktop app that runs on your own computer, so you can process sensitive data with privacy.
(former Google Refine) OpenRefine is a powerful tool for working with messy data, cleaning it up, transforming it from one format into another, extending it with web services, and linking it to databases like Freebase.
Meaningo has developed a powerful semantic search engine currently dedicated to online shopping integrated with a decision-making support system that offers the user an easy way to refine and control the affinity quality of the search (patent pending P-79643-US).