Yahoo Search BOSS (Build your Own Search Service) is a Yahoo! Developer Network initiative to provide an open search web services platform.
In 2012, Yahoo expanded their Yahoo Search BOSS platform to provide additional services such as BOSS Hosted Search to enable any website owner to embed Yahoo web search experience for free on their site.
The main goal and idea of BOSS is to give users, in this case developers, access to the Yahoo Searchindex for a small fee. The results can be supplied into the developer's website or program so that they can manipulate the resources according to their product's requirements. BOSS allows the results to be returned in XML, JSON, HTML, text and also allows the comprehensive search feature allowed in Yahoo like pulling the results by pages, searching inside PDF, etc. The ranking of the websites for a search term is the same as the Yahoo Search ranking since both of these are pulling from the same index and ranking.
One of BOSS's key differentiators was the free use of BOSS as a white label, no ads required service. By using Yahoo's search engine, which has had millions in R&D invested in it in the years since Yahoo boomed in the 1990s, web developers are able to get much higher quality results than if they built their own search engine. On Aug 17th, 2010 Yahoo stated that BOSS would require some sort of ad or fee-based model to sustain itself.