Yahoo is making several APIs available
- Yahoo Developer Network
- Yahoo APIs and Web Services
Yahoo can provide data back as XML or Json. Interesting links for using Yahoo services.
Show Object Properties
- How to use returned XML from Yahoo Services with Silverlight
Silverlight: Using Returned XML
- Interesting article on parsing Json safely
- Excellent Json validator. Not only validates, nicely formats the stream which comes from Yahoo (Json data) so that you can copy the input to a word document to understand the data structure.
JSONLint The JSON Validator
- JSON Primer