Abstract: Several embodiments of the present invention employ synchronization adapters for synchronizing information between “WinFS” and non-“WinFS” data sources. Examples of adapters include an adapter that synchronizes address book information between a “WinFS” contacts folder and a non-WinFS mailbox. In these instances, adapter developers might use the “WinFS” synchronization core services API described herein for accessing services provided by the “WinFS” synchronization platform in order to develop schema transformation code between the “WinFS” schema and the non-“WinFS” data source schema. Additionally, the adapter developer provides protocol support for communicating changes with the non-“WinFS” data source. A synchronization adapter is invoked and controlled by using the synchronization controller API and reports progress and errors using this API.