Abstract: A computer system is described comprising one or more servers, one or more user terminals; and a database of computer entries, each computer entry including node data defining a node representative of an entity and link data defining a plurality of links connecting the node to one or more other nodes representative of one or more other entities, each link having associated tag data that describes an attribute of one of the entities associated with the link and a reputational score associated with the attribute. The computer system is able to search the computer entries based on a search request; to rank search results based on reputational scores associated with the search results; and to output one or more ranked search results. The computer system also allows entities to add new links into the database and to add new nodes representing new entities into the database.