Yahooon Thursday launched a new service called Yahoo! Search BOSS, which allows small search engines and Web sites to add Yahoo! searches to their query results.

"Build Your Own Search," or BOSS allows any Web site will be able to assemble a search engine using Yahoo's system for indexing information and images on the Internet. Yahoo figures plenty of Web developers will be interested because it's providing access to a set of tools that would cost more than $300 million to build from scratch. BOSS also lets search engines and Web sites rank search results to their liking.

Yahoo! is also planning on serving ads to search engines and sites that use BOSS and split ad revenues with them.

"Today, the search market is generally limited to three major search engines to drive innovation and growth," said Prabhakar Raghavan, chief strategist for Yahoo! Search. "BOSS opens up the playing field for developers and companies to disrupt the search market, become principals in search and build new Web search experiences that offer more choice for users."

BOSS will offer two options for companies and developers. Today, developers can begin using the BOSS API and the mash-up framework tools and see examples of how they could deploy BOSS on their sites by visiting the Yahoo! Developer Network site, http://developer.yahoo.com/boss. The self-service API allows developers to quickly get started in creating new Web search experiences.

The BOSS Custom service will be offered to select partners with large-scale needs in building and supporting Web search experiences.

Two specialty search services, Hakia and Me.dium, already have agreed to participate in the BOSS program.

Having fallen so far behind Google that it became a takeover target, Yahoo is banking on the creativity of other Web developers to help regain ground in the Internet search advertising market.