17. A system to allow a user to search a fact repository, comprising: one or more processors; and memory storing one or more programs for execution by the one or more processors, the one or more programs comprising instructions to: receive a search query from an object requester; retrieve at least one fact from a fact repository, the at least one fact corresponding to the received search query and having an attribute and a value, wherein the fact repository includes a plurality of facts associated with objects, wherein a respective fact in the fact repository includes a respective attribute and a respective value, wherein the respective value is a text string and wherein the plurality of facts are extracted from a plurality of documents; retrieve at least one annotation associated with the at least one fact, the annotation having a value corresponding to the value of the at least one fact, wherein an annotation includes additional information about a fact, and wherein a value of the annotation is indexed to a substring of a fact's value; send the attribute and value of the at least one fact and the annotation in response to the query; and send the retrieved annotation in response to the query.
17. A system to allow a user to search a fact repository, comprising: one or more processors; and memory storing one or more programs for execution by the one or more processors, the one or more programs comprising instructions to: receive a search query from an object requester; retrieve at least one fact from a fact repository, the at least one fact corresponding to the received search query and having an attribute and a value, wherein the fact repository includes a plurality of facts associated with objects, wherein a respective fact in the fact repository includes a respective attribute and a respective value, wherein the respective value is a text string and wherein the plurality of facts are extracted from a plurality of documents; retrieve at least one annotation associated with the at least one fact, the annotation having a value corresponding to the value of the at least one fact, wherein an annotation includes additional information about a fact, and wherein a value of the annotation is indexed to a substring of a fact's value; send the attribute and value of the at least one fact and the annotation in response to the query; and send the retrieved annotation in response to the query. 22. The system of claim 17 , wherein the facts are extracted from the plurality of documents without user interaction.