However, the presence of RSS is directly responsible for the existence of search aggregators and a critical component in the behind-the-scenes technology.
In 2005 Amazon published the OpenSearch specification for making search results available in a generic XML format.
However, while OpenSearch syndication allows for greater flexibility in the way Search Aggregators display results, it is generally not required.
A parameterized URL looks something like this: In this case, the {SEARCH_TERMS} parameter would be replaced with the user requested search terms, and the query would be sent to the host.
Apple patent US6847959B1,[2] filed January 5, 2000, covers universal search aggregation.