Yahoo Lets You Be BOSS
In an attempt to beef up its ad-search business by opening up its search technology, Yahoo has launched a new program called BOSS (Build your Own Search Service). The move is part of the new "Yahoo Open Strategy", a strategy that aims to attract more users and developers to Yahoo's technology and services by opening them up. It's not a totally free lunch, of course, as traffic over a certain "query threshold" will require some type of agreement with Yahoo, either hosted ads, revenue, or some type of exclusivity agreement.
With this first release of BOSS developers can fetch search content for Web, News, Image, and Spelling Suggestions. The API itself is a RESTful web service, with the option to receive data back from the service in JSON or XML formats. Full documentation on the search API is here.