Yahoo! has rolled out a limited preview of its Search Monkey platform, a way for third-party web developers to "enhance the functionality, appearance and usefulness" of Yahoo! Search results.

The company likes to say that this new platform has "opened up" its search engine. With Search Monkey, first announced in February, third-parties can build online services that feed straight into the pages Yahoo! serves up to web surfers.

These third-parties might be companies looking to tweak information that turns up alongside their own urls. "Site owners can build enhanced search results that will provide searchers with a more useful experience by including links, images and name-value pairs in the search results for their pages," Search Monkey chief Amit Kumar writes on the Yahoo! Search Blog.

But the platform also allows dev types to create mini-applications that tweak entire categories of search results. "Developers can build Search Monkey apps that enhance search results, access Yahoo! Search's user base and help shape the next generation of search."

For instance, the Web 2.0-happy restaurant review site Yelp could build an app that transforms restaurant search results, moving from this:

Before Search Monkey

To this:

After Search Monkey

And eventually, the average surfer will be free to the pick and choose between these mini-apps. "Users can customize their search experience with apps built by or for their favorite sites."

Yahoo! says Search Monkey will be available to everyone "in a few weeks." Eager developers are invited to a launch party on May 15.

The world's second largest search site also says that Search Monkey is just the first taste of something called the Yahoo! Open Strategy (Y!OS for short). Eventually, the company insists, it will allow developers to write applications that beef up all sorts of other services, including Yahoo! Mail, My Yahoo!, the Yahoo! front page, and the site's mobile tools. ®