Yahoo will make its Search Monkey platform available to all developers on Thursday, another step in its wide-ranging effort to open up its sites and services.

Search Monkey is Yahoo's initiative to let external developers create applications to enhance its Web search results and, in theory, make them more appealing and useful.

"We're responding to people's demands to be able to complete tasks in search results," said Amit Kumar, Director of Product Management for Yahoo Search. "We're focused on creating a better search experience for our users and want to let developers with an understanding of structured data jump start the system with their apps."

It is the first component of Yahoo's broad Open Strategy, announced last month and described as a long-range plan to open all Yahoo sites, online services, and Web applications to outside developers, and give users a "social profile" dashboard to unify and manage their Yahoo services.

With Open Strategy, Yahoo wants to improve its position in key areas like search and social networking, and compete better against Google, MySpace, and Facebook.

IDC analyst Susan Feldman called Search Monkey a "really important" initiative that can differentiate Yahoo from Google. "From a market point of view, that's a great idea," she said.

From a technology perspective, if users can let Yahoo factor into search what it knows about them, "the experience will be quite different and it should also improve relevance," Feldman said.

The Search Monkey development platform, which has been in a closed beta test for the past several weeks, can be used by any outside developer and doesn't require Yahoo approval.

At the moment, developers can create two types of Search Monkey applications. One type, called Enhanced Results, acts as a richer, more useful replacement for standard search results, and can only link to the site in question. The other type, Infobar, opens up below a search result and can include complementary data and links to other related sites.

Kumar said that for now, Search Monkey will be specifically for applications for Yahoo's general Web search engine and not for its specialty engines for specific results like images and news.

In a few weeks, Yahoo expects to launch a gallery of Search Monkey applications that users of its Web search engine can install, he said.

Although there is no revenue-generating potential for Search Monkey applications, Yahoo is holding a contest called the Search Monkey Developer Challenge with $20,000 in prizes. Developers have until June 14 to submit their applications for consideration. Prizes will be awarded in several categories, including Best Enhanced Result, Best Infobar and Best Data Service.

This story was updated on May 15, 2008