Facilitation of a cross-server extension

Servers at different locations and storing different data can be designed such that one server can act as an extension of the other server by accepting search queries from the other server and returning a response. The response can also comprise results, from the querying server, from within its own document collection. The other server can then include in its response to its user's queries, results obtained from its extension. One or more of the servers can act as an aggregation server that aggregates data from other servers before sending the data to a querying device or server. Additionally, the aggregation server can modify, add, or delete information from the results, before sending to the querying device, based on previous rules and/or properties associated with the aggregation server.