Yahoo! Developer Network - Allows users to access Yahoo! content and services in their favourite programming languages.
Fire Eagle - Allows users to share their location with sites and services through the Web or a mobile device. Fire Eagle also gives developers tools to build and use location-aware applications and services.
Yahoo! Maps APIs - Offers a set of Yahoo! Maps APIs for both Flash and AJAX that enable programmers to use and publish maps on web sites or in client applications.
Yahoo! Search BOSS - BOSS (Build your Own Search Service) provides turnkey access to Yahoo! Search infrastructure and technology using the BOSS API to create unique search experiences on other sites.
Yahoo! Search Web Services - Allows access to Yahoo!'s Search APIs and SDK, to build Yahoo search services directly into applications.