31. A method of re-ranking a list of documents obtained from a search wherein a ranking of a document in the list is determined by a relevance of the document to a search text, the method performed by a computer processor, having a scalable time complexity of O(N x ) where 0<=X<=1.0, and comprising: classifying the list of documents so that each document in the list has a fingerprint, said fingerprint comprising a list of weights associated with particular topic categories in a classification system, each of the weights representing a degree to which the document relates to the particular topic category that the weight is associated with, the weights obtained automatically from a computer program, providing a user fingerprint, the user fingerprint comprising a list of cumulative weights associated with particular topic categories in the classification system, each of the cumulative weights representing a degree to which text or texts in a link recently accessed by a user relates to the particular topic category that the cumulative weight is associated with, the cumulative weights obtained from weights that in turn were obtained automatically from a computer program, searching the list of documents by comparing the user fingerprint with the fingerprint for each document in the list of documents, and re-ranking the list of documents based on a degree to which a fingerprint of the document in the list has a mathematical overlap with the user fingerprint, the method configured to re-rank the list of documents based on relevance to the search text whether the list of documents includes text written in one language or in more than one language.
31. A method of re-ranking a list of documents obtained from a search wherein a ranking of a document in the list is determined by a relevance of the document to a search text, the method performed by a computer processor, having a scalable time complexity of O(N x ) where 0<=X<=1.0, and comprising: classifying the list of documents so that each document in the list has a fingerprint, said fingerprint comprising a list of weights associated with particular topic categories in a classification system, each of the weights representing a degree to which the document relates to the particular topic category that the weight is associated with, the weights obtained automatically from a computer program, providing a user fingerprint, the user fingerprint comprising a list of cumulative weights associated with particular topic categories in the classification system, each of the cumulative weights representing a degree to which text or texts in a link recently accessed by a user relates to the particular topic category that the cumulative weight is associated with, the cumulative weights obtained from weights that in turn were obtained automatically from a computer program, searching the list of documents by comparing the user fingerprint with the fingerprint for each document in the list of documents, and re-ranking the list of documents based on a degree to which a fingerprint of the document in the list has a mathematical overlap with the user fingerprint, the method configured to re-rank the list of documents based on relevance to the search text whether the list of documents includes text written in one language or in more than one language. 34. The method of claim 31 , wherein a selected number of weights is between 1 and 75 and the classification system is the Dewey Decimal System.