All feed responses are available as XML or JSON. We discuss the merits of both when deciding which to use in your implementation.
XML
By default all feeds are provided as XML. Many customers decide to use XML as they can validate and verify the XML using our public XSD schema, which is available at companyname.frommers.biz/frommers/feedschema/base.xsd (example). Numerous libraries are freely available that help simplify the ingestion, caching and query of XML documents.
Customers have had success using the following libraries, although every implementation is different.
JSON
With a simple use of one request parameter, feedType=json, (example) all feeds can be converted to return a JSON response. JSON is most useful when implementing a pure Javascript solution, rather than using traditional languages like Java or dynamic languages like PHP. Many libraries are available to help implement a JSON solution but the most favored are jQuery and Prototype. Caching can be problem with JSON as it has to be done on the client side. However, there are existing AJAX patterns that can help with create Browser-Side Cache for feed responses.