Wikipedia
DeeperWeb
DeeperWeb is a free metasearch engine for information on the World Wide Web that employs tag cloud techniques for navigating through Google search results. Topic Map methods give results relevant to a specific topic.
The tool can be used through Google's website or a Firefox extension. A search plugin allows searching directly from the Internet Explorer 7 and 8, or Firefox 3+ web browsers' search box.
On May 5, 2009, The DeeperWeb Team announced a beta release, which received some favorable welcomes. DeeperWeb's concept is based on a research article written by the company founders, which examines the relationship between the core search engines and the Vertical search markets.