Mercurius is a unique web search tool that helps you to narrow search engine and metasearch searches by listing Palabras clave and phrases extracted from the web sites returned by a search. You can then repeat the search using any listed Palabras clave you think are relevant, enabling you to reduce the number of results and find what you want. For example, a search on "William Shakespeare" returns more than a million results, but by using Mercurius and selecting "Ben Jonson" and "quote" from its list of suggested Palabras clave, the search narrows to just a few hundred results, the first of which give Jonson's famous quote about Shakespeare being "not of an age, but for all time". So Mercurius search assistant can a) guide you to Palabras clave that would give you a better result when you repeat a search, b) reveal connections that you didn't know existed, and c) jog your memory as to what exactly you're searching for. It works with Microsoft Internet Explorer and most of the major search engines and metasearcher sites.