1. A method of executing computer instructions on a server computer that includes at least one processor and at least one physical memory, the method comprising: acquiring the computer instructions from the at least one physical memory; executing the acquired computer instructions on the at least one processor; storing in the at least one physical memory any results of the executing of the acquired computer instructions on the at least one processor; processing, by the server computer, one or more digital signals received from one or more first remote user computing platforms via a communication network, wherein the one or more digital signals comprise identities of a plurality of federated search sources and one or more user-submitted index keywords to indicate content of the plurality of federated search sources, the plurality of federated search sources comprising at least one search source which is uncrawled and not publically available, the plurality of federated search sources further comprising at least one first federated search source and at least one second federated search source, individual ones of the plurality of federated search sources comprising links to multiple different specified sources of electronic digital signal quantities; indexing, by the server computer, at least one of the plurality of federated search sources to determine index criteria and to determine at least one federated search source of the at least one first federated search source and the at least one second federated search source related to individual index keywords that comprise at least the one or more user-submitted index keywords, wherein the indexing is based at least in part on matching domains of an indexed federated search to domains of a search engine to return results based at least in part on a category path, wherein the category path of the indexed federated search results is to be matched against a category path associated with a crawler-based search, and wherein the indexing further comprises: retrieving, by the server computer, the one or more digital signals comprising the electronic digital signal quantities from sites associated with a federated search; extracting, by the server computer, weighing factors from the one or more digital signals including at least keywords and the domains; and creating, by the server computer, a table of a plurality of signatures based at least in part on the weighing factors: storing, by the server computer, the index criteria in a database in the at least one physical memory; processing, by the server computer, a query received via the network from a second remote user computing platform after performing the indexing; executing, by the server computer, a web searching protocol to search the at least one of the plurality of federated search sources; determining, by the server computer, one or more signatures of the plurality of signatures associated with one or more of the plurality of federated search sources based at least in part on the index criteria; matching, by the server computer, the query with the determined one or more signatures based, at least in part, on the index criteria to determine and rank one or more of the plurality of federated search sources for the query in accordance with a usefulness metric; and at least partially in response to a user selection of one or more of the ranked one or more of the plurality of federated search sources, performing, by the server computer, a federated search, and transmitting electrical signals via the communication network to the second remote user computing platform, the electrical signals comprising results including respective links to the one or more ranked federated search sources for the query and at least one displayable graphical indicator of the usefulness metric for individual ones of the one or more ranked federated search sources.