Some OpenSearch sites for reference
Do you know www.opensearch.org? This is a open standard for search engines, which is created by A9.com from Amazon.
Why does it matter? Don't look at all those boring documents on opensearch.org, generally speaking, this is a standard that requires search engines return a RSS/ATOM feed. So you can use your favorite feed reader, get the best answers just in time.
Meanwhile, a standard RSS feed allows you intergrate different search engine results into your own application. For example, you have a enterprise search engine inside your company, but you want to intergrate some search results from outside, an iframe is okay but not very good. With XML+XSLT, you can intergeate them very easily. This is not limited to search engines, you can try different ideas, Yahoo Image Search, Google News Search, Live Spaces Search, LinkedIn expert search... Anything.
Well, what if a site does not return RSS feed? Wikipedia, Linkedin, they don't have anything. Oh, Wikipedia said they support opensearch, but they only support a part of the standard. What they returned can only be used in IE7/Firefox live search.
Live.com has a very useful feature to solve this problem. It can return RSS feed for any results. To give wikipedia a RSS feed, just use
http://search.live.com/results.aspx?q={searchTerms}+site%3aen.wikipedia.org&format=rss
And that's all.
Here I list some of the sites to be used with RSS feed:
