Yahoo is allowing users to develop their own search engines with a package known as Build your Own Search Service (Boss).

The tool will let users create search engines to retrieve customised results on their own sites.

The service taps directly into Google search APIs and allows users to put the search data within their own interfaces and add them to data from other web services.

Yahoo said that users will be able to create customised search engines which can return results based on user preference or social networking connections, all while drawing from Yahoo's own search index.

The service is being offered as an alternative to Yahoo's previous search API tool, which restricted the ordering and presentation of the results, as well as a strict limit of 5,000 queries per day.

Google released a similar service in 2006, allowing users to specify a custom set of sites and criteria for search results.

Yahoo, however, hopes to take Boss far beyond this, possibly even leading to the creation of new search engines.

"It lets users realise their own vision of what a search experience should be, enabling unlimited mash-ups and disrupting the search landscape," said Prabhakar Raghavan, chief strategist at Yahoo Search.

"Boss will enable developers and companies to enter the search industry without large capital or resource expenditures, unleashing a wave of search innovation beyond any of today's search principals."