iSync is a software application published by Apple Inc. It runs only under Mac OS X and is used to synchronize contact and calendar data from Address Book and iCal with many non-Apple SyncML-enabled mobile phones via a Bluetooth or USB connection. Support for many (pre-October 2007) devices is built-in, with newer devices being supported via manufacturer and third-party iSync Plugins. Support for Palm OS organizers and compatible smartphones was removed with the release of iSync 3.1 and Mac OS X 10.6 Snow Leopard. BlackBerry OS, Palm OS, PocketPC and Windows Mobile OS devices cannot be used with iSync, but are supported by third-party applications. Prior to the release of Mac OS X 10.4, iSync could also synchronize a users Safari bookmarks with the MobileMe subscription service provided by Apple.