From their site: You build great web applications. We have millions of users who store their data on Yahoo!. Browser-Based Authentication (BBAuth) makes it possible for your applications to use that data (with their permission). BBAuth also offers a Single Sign-On (SSO) facility so that existing Yahoo! users can use your services without having to complete yet another registration process. The first time a user visits your web site, you redirect them to a specially constructed Yahoo! URL where they can login and grant your application permission.
The following is a list of how-to and tutorial content that matched your search term. ProgrammableWeb's how-to content comes from two sources; full-blown tutorials that we publish ourselves and other highly relevant tutorials that we find elsewhere on the Web. This list represents on combination of both tutorial types and if you go to ProgrammableWeb's API University, you'll not only be able to find more, they are organized based on your role (API providers or developers who consumes APIs). If you know of a tutorial that would be of interest to the ProgrammableWeb community, we'd like to know about it. Be sure to check our guidelines for making contributions to ProgrammableWeb.