The SearchMetrics PHP SDK by SearchMetrics allows API communication to integrate search features into applications. Currently, the SDK supports HTTP protocol. In addition to authentication with PHP, SearchMetrics permits OAuth requests.
SEOmoz, a leader in SEO software, has offered link intelligence APIs for a few years (Mozscape being the latest). Although Mozscape has garnered high adoption rates (over 10 million requests/day), customer feedback uncovered shortcomings. SEOmoz now knows that 10 requests/second and a max of 50 URLs/batch "is not able to support everyone's use case." Accordingly, SEOmoz enhanced Mozscape API capabilities and is currently in beta. Although the beta is in its early stages, throughput has increased 400%.
While Google leads the way in web search and Yahoo leads the way in answers, many upstart services are attempting to help you make decisions by giving you smarter answers to your questions. Microsoft has billed its new search offering Bing as both a "decision engine" and an "answer engine." Now there's Hunch, a new start-up founded by Flickr's Caterina Fake, which also aims to be a decision engine, but using a very different model. By first asking the user questions ranging from food preferences to pet peeves, Hunch tries to provide answers to questions that best match the user's interests based on crowdsourced data collected from other users.