A computer method of gathering and summarizing large amounts of information comprises collecting information from a plurality of information sources (14, 51) according to respective maps (52) of the information sources (14), converting the collected information from a storage format to XML-language documents (26, 53) and storing the XML-language documents in a storage medium, searching for documents (55) according to a search query (13) having at least one term and identifying the documents (26) found in the search, and displaying the documents as nodes (33) of a tree structure (32) having links (34) and nodes (33) so as to indicate similarity of the documents to each other.