A9.com invented the OpenSearch technology for search aggregation in 2004.

OpenSearch is a set of simple formats for the sharing of search results. Any website that has a search feature can make their results available in OpenSearch format. Other tools can then read those search results. For example, here is an aggregator that brings together search results from many websites:

A9.com's own OpenSearch Client incorporates the search results from many websites. Read more about the Client on our sidebar to the right.

OpenSearch is an open format with a Creative Commons license. It uses the popular syndication formats RSS and Atom, along with a document describing the search engine.

• Submit Your Search. You can make your own search available in A9.com's OpenSearch Client by submitting your search to A9.com.
• OpenSearch.org. This site provides detailed specifications, full documentation, and access to community resources. For more information on the OpenSearch specification, visit the OpenSearch.org website.

All components of the OpenSearch 1.1 specification are made available by A9.com subject to the terms of the Creative Commons Attribution-ShareAlike 2.5 License (the License). The License applies only to the OpenSearch specification, and not to any other technology or copyrightable works of A9.com or its affiliates.

Our OpenSearch Client is a web application built on the OpenSearch specification. We aggregate search results from a large number of websites to provide a custom selection of results based on your interests.