9. A system for submitting search requests to at least two search engines and presenting search results therefrom customized using content preferences learned about a user, the system comprising: a computer memory store comprising instructions in computer readable form that when executed cause a computer system to send query information to the at least two search engines, the query information including (a) a query identifying desired content, and (b) user information, the user information including (i) context information describing the environment in which the query information is being sent, the context information adapted into a syntax understandable by at least one of the at least two search engines, and (ii) a user signature representing content preferences learned about the user; receive at least one set of a search result and auxiliary information from the at least one of the at least two search engines in response to sending the query information, the auxiliary information of the set including information describing attributes of the search result of the set that led to the search result being chosen by the at least one of the at least two search engines; order the at least one search result based at least in part on the auxiliary information; and present the ordered search results to the user.
10. The system of claim 9 , wherein the auxiliary information includes at least one of: an identification of a dataspace associated with the corresponding search result, an identification of a search engine that provided the search result, a relevance list, wherein a relevance list element represents a set of an attribute of the search result and a value indicating the relevance of the attribute to at least one of the query and the user information, a textual location list, wherein a textual location list element represents the location of search terms from the query information in fields provided by the search result, a disjunction indicator list, wherein a disjunction indicator list element represents whether a corresponding search term from the query information matched the search result, a spelling correction list, wherein a spelling correction list element represents whether a corresponding search term from the query information exactly matched a substring of fields from the search result, and wherein the spelling correction list element represents a value indicating the distance between the corresponding search term and the matched substring, if a match was based on an applied spelling correction, a complete word match list, wherein a complete word match list element represents whether a corresponding search term from the query information exactly matched a full word of fields from the search result based on an applied spelling correction, a field match list, wherein a field match list element represents whether the search query matched all words of a field of the search result, a location proximity indicator representing a value for the distance from the search result to a specified location, and a location query-place indicator representing whether a part of the search query matched an entity recognized to be a place having a location.