More commonly referred to as the “Deep Web“, it’s defined as “World Wide Web content [that is] not part of the surface Web indexed by search engines”. I prefer deepnet myself because a) I can use it for the word of the day, and b) it sounds cooler.

I found a reference to it while searching for DARPA on Google, and was interested to discover that they had funded (along with a host of other US groups like the NSA and the US Air Force) an AI-based deep web search engine that is now being run under a commercial company called Fetch. According to another news article on Computer World, the search is “used by government agencies seeking to rapidly import and integrate data from multiple Web sites and databases for emergency response, location intelligence and antiterrorism efforts”.

Yet another great example of how the military-industrial complex continues to drive technology.