Sync Framework Toolkit builds on the Sync Framework 2.1 and uses OData to sync with any platform or client, including Windows Phone 7, Silverlight, Windows Mobile, iPhone, iPad, Blackberry, Android devices, and any browser using HTML5.
The Sync Framework toolkit provides the capabilities that was promised in Sync Framework v4.0 – the version for which there was CTP in October 2010, but never saw a full release. As explained in this forum thread, the release has been postponed indefinitely, but to help teams who have already developed against the CTP, a toolkit was planned which works on top of Sync Framework 2.1.
Even earlier, Sync Framework could be used for synchronizing non-MS databases. The limitation was, it had to be installed on the client, which could be done only on Windows – something that’s not needed now. Rob Tiffany, Mobility Architect at Microsoft, explains the major improvements introduced in the Toolkit in his blog post.
As to why developers would want to use the Sync Framework for data transfer rather than SOAP or REST, Rob states:
The reason has to do with performance and bandwidth efficiency. Using SOA, one would retrieve all the data needed to the device in order to see what has changed in SQL Server. The same goes for uploading data. Using the Sync Framework Toolkit, only the changes, or deltas, are transmitted over the air.
The toolkit documentation explains how to write clients for both conflict-aware as well as conflict-unaware clients so as to consume a sync service from any platform. Along with the samples for Windows Phone, the toolkit also contains a sample iPhone app as well as an offline HTML5 application. The client-side source samples in the package are released under the Apache 2.0 license whereas the server-side source code is released under MS-LPL license.
Sync Framework is a synchronization platform from Microsoft that can be used to synchronize data across multiple data stores.