From their site: The Digg Application Programming Interface (API) has been created to let users and partners interact programmatically with Digg. Digg is a place for people to discover and share content from anywhere on the web. From the largest sties to the smallest blogs, Digg surfaces the best stuff as voted on by users. The API returns Digg data in a form that can be integrated into an application or a web site. The API is available to everyone free of charge, but its use is subject to acceptance of the API License Agreement.