The brainchild of Dr. Riza C. Berkan, tries to anticipate the questions that could be asked relating to a document and uses them as the gateways to the content.
The image search engine was unique for its host of options to narrow down search based on image size, color and content.
See where it happened on a map. For each Wikipedia article, we've made a map showing all the locations mentioned on that article on a Google map.
Not a search engine as such but.....it's a computational knowledge engine: it generates output by doing computations from its own internal knowledge base, instead of searching the web and returning links.