Introducing the Yahoo! Site Explorer APIs
Gain a unique perspective on your online presence with Site Explorer APIs
Yahoo! Site Explorer APIs provide access to information about your site from the Yahoo! Site Explorer service. These APIs help you better understand your traffic and usage — querying for the pages in the Yahoo! index and the sites linking into a site. They will be useful to anyone looking for a good grasp of who is linking to you and to create an effective alternative to easily-spammed trackbacks.
Source: Site Explorer APIs from Yahoo! Search Web Services
After creating a sitemap I decided to explore the SEO features available from Yahoo since I got the impression that Yahoo supports the sitemap protocol. Lo and behold, the rumors are true and Yahoo looks like they are happy to use the same sitemap.xml that Google uses. The sitemap support for MSN is under development.