OpenCalais extends CQ5’s built in tagging & SEO support by automatically analyzing submitted text and generating rich semantic metadata, part of which are entities that can be used for content tagging. OpenCalais uses many techniques to generate this metadata including natural language processing and machine learning. The toolkit can find entities like people, places, organizations, technical terms and many, many others.
Check out the blog post outlining the integration and a link to download the CQ5 package. Great work guys!