18. An apparatus comprising: a processor; and a storage device coupled to the processor, wherein the storage device stores one or more sequences of instructions, which when executed by the processor causes the processor to perform: a search engine receiving one or more distinct taxonomies and an environment identifier from an administrator of an environment; storing taxonomies received from a plurality of environments, wherein each taxonomy of the one or more distinct taxonomies is stored in association with the environment identifier; wherein said each taxonomy specifies categories and relationships between the categories; receiving a search query; determining a particular environment identifier of a particular environment that is associated with the search query; selecting one of a plurality of taxonomies stored in association with the particular environment identifier; and generating a search engine results page, at least in part, by applying to a search engine result item a set of rules that are associated with the selected taxonomy; wherein applying the set of rules to a search engine result item identifies a set of categories in the selected taxonomy to display on the search engine results page in association with the search engine result item.
18. An apparatus comprising: a processor; and a storage device coupled to the processor, wherein the storage device stores one or more sequences of instructions, which when executed by the processor causes the processor to perform: a search engine receiving one or more distinct taxonomies and an environment identifier from an administrator of an environment; storing taxonomies received from a plurality of environments, wherein each taxonomy of the one or more distinct taxonomies is stored in association with the environment identifier; wherein said each taxonomy specifies categories and relationships between the categories; receiving a search query; determining a particular environment identifier of a particular environment that is associated with the search query; selecting one of a plurality of taxonomies stored in association with the particular environment identifier; and generating a search engine results page, at least in part, by applying to a search engine result item a set of rules that are associated with the selected taxonomy; wherein applying the set of rules to a search engine result item identifies a set of categories in the selected taxonomy to display on the search engine results page in association with the search engine result item. 19. The apparatus of claim 18 , wherein the one or more sequences of instructions, which when executed by the processor causes the processor to perform: accessing a table that stores associations between search result items and categories in the selected taxonomy.