Yahoo! has not been able to resist the change of the times. Following the steps of the leading competitor regarding Web Search, Google, it has finally opened its platform to developers and companies, allowing the usage of the Yahoo! index's vast amounts of web documents for developing innovative applications:
BOSS (Build your Own Search Service) is Yahoo!'s open search web services platform. The goal of BOSS is simple: to foster innovation in the search industry. Developers, start-ups, and large Internet companies can use BOSS to build and launch web-scale search products that utilize the entire Yahoo! Search index. BOSS gives you access to Yahoo!'s investments in crawling and indexing, ranking and relevancy algorithms, and powerful infrastructure. By combining your unique assets and ideas with our search technology assets, BOSS is a platform for the next generation of search innovation, serving hundreds of millions of users across the Web.
A big point is that there is no limit in the number of searches per day. I remember that Google had a limit in the number of searches, and in results retrieved, some time ago; it seems that limit has disappeared!
Now it is the moment to play with Yahoo!'s and Google's search APIs, and to compare!