Yahoo will soon be allowing third parties to enhance the Yahoo Search experience. The new platform, codenamed “SearchMonkey” and officially called Open Search Platform, will consist of a set of APIs that allow third parties to modify search results on Yahoo by adding images, structured data and additional deep links.

The altered results can contain far more information than the current link and a bit of text from the website. For example, Yelp (a user generated local business review site), one of the launch partners, will include a photo, review information and the address and phone number of the business.

Some modifications will be turned on for users by default; others will only appear for users who’ve chosen to add them. Amit Kumar, the product lead for the Open Search Platform, says that the desired effect is similar to Greasemonkey, a Firefox addon that allows users to see modified versions of websites (thus the codename SearchMonkey).

Third parties will have an incentive to get users to add their Yahoo search modification, which in turn can drive more traffic to their sites. One thing third parties cannot change, though, are the order of results (see Erick’s post that touches on this issue here). They can simply change the way a result linking to one of their pages appears to the searcher, and add additional rich media and links to structured data.

When this launches anyone will be able to create their own modifications and promote them – users can add as many as they like.

Below is a screenshot of a different search, for “hillary clinton.” The New York Times has altered the result to include links to other election news, debate analysis, and added data for current delegate count and total money raised: