The open Yahoo! API is a great resource to work with. There is plenty of documentation for web developers, along with live demos and examples. What makes the application so interesting is how Yahoo! manages so many different online services. Along with their search engine there is also Yahoo! news, maps, weather, and so much more.
For this tutorial I’d like to focus on the Yahoo! Answers API. We will be creating a simple webapp that pulls all recently answered questions from a select few categories. The API delivers results via XML or JSON, so we have the option to build with any backend programming language. Although for this guide I’ll stick to PHP since it’s the most commonly understood backend language.