11. A computer for implementing notifications, the computer comprising: a memory for storing data defining notification operations, the data defining notification operations comprising a hierarchy of Uniform Resource Identifiers (URIs) and Extensible Markup Language (XML) document schema defining XML documents; an interface for receiving a notification command comprising an URI identifying a notification resource and a Hypertext Transfer Protocol (HTTP) GET method; and a processor for: determining a notification operation based on the data defining notification operations stored in the memory and the notification command received; obtaining a list of notifications indicated in the notification; and returning a NotificationList XML document.
15. The computer according to claim 11 , wherein the URI of the notification command comprises a query string.