Яху сделал ход конем:

открыл поисковый индекс через Апи. Убраны ранее замеченные ограничения на использование. Если сравнивать с Google Custom Search Engine, или Google Ajax Search API - выглядит очень заманчиво.

Our goal with BOSS (Build your Own Search Service) is simple -- foster innovation in the search landscape. As anyone who follows the search industry knows, the barriers to successfully building a high quality, web-scale search engine are incredibly high. Doing so requires hundreds of millions of dollars of investment in engineering, sciences and core infrastructure -- from crawling and indexing technology to relevancy and machine learning algorithms, to stuff as mundane as data centers, servers and power. Because competing successfully in web search requires an investment of this scale, new players have effectively been prohibited from delivering credible alternatives to Yahoo! and Google. We believe the BOSS platform will begin to change that.

So what is BOSS?
BOSS is a new, open platform that offers programmatic access to the entire Yahoo! Search index via an API. BOSS allows developers to take advantage of Yahoo!'s production search infrastructure and technology, combine that with their own unique assets, and create their own search experiences. While search APIs have been available for some time, BOSS removes many of the usage restrictions that have prevented other companies from using them to build innovative new search engines.

Here's a quick summary of what's available today:

Ability to re-rank and blend results -- BOSS partners can re-rank search results as they see fit and blend Yahoo!'s results with proprietary and other web content in a single search experience
Total flexibility on presentation -- Freedom to present search results using any user interface paradigm, without Yahoo! branding or attribution requirements
BOSS Mashup Framework -- We're releasing a Python library and UI templates that allow developers to easily mashup BOSS search results with other public data sources
Web, news and image search -- At launch, developers will have access to web, news and image search and we'll be adding more verticals soon
Unlimited queries -- There are no rate limits on the number of queries per day
These capabilities are really just a first step -- we're already working on expanding the API functionality and providing more access to Yahoo! Search Technology.
In addition to a self-serve API, we're also partnering with a handful of Internet companies with large user bases or unique assets to collaboratively develop next gen search products using Yahoo!'s full suite of search technology.

http://www.ysearchblog.com/archives/000599.html

Детальнее о BOSS:
http://developer.yahoo.com/search/boss/custom.html