Google Calendar Sync is a program released by Google on March 5, 2008.http://googleblog.blogspot.com/2008/03/google-calendar-sync.html The software sends information between Google Calendar and Microsoft Outlook. Calendars can sync items two ways, making them appear both on Microsoft Outlook and Google Calendar, or one way, bringing information only to one or the other.http://www.google.com/support/calendar/bin/answer.py?answer=89960 Google Calendar Sync is available for both Windows XP and Windows Vista and is compatible with Microsoft Outlook 2003 and Microsoft Outlook 2007.

Multiple tools have been created to sync Google Calendar with systems and programs not supported by Google Calendar Sync. Spanning Sync is a program which syncs Apple's iCal software with Google Calendar. It is free to try for 15 days, or can be bought for $65.http://spanningsync.com/ GooSync is a freeware program that can be used to connect mobile phones that use SyncML to Google Calendar. These include the BlackBerry and most Nokia and Sony Ericsson phones.http://googlesystem.blogspot.com/2007/06/sync-your-mobile-phone-with-google.html Other programs include GMobileSync for PocketPC and Windows Mobile devices and Calgoo which syncs Google Calendar and iCal for free.http://googlesystem.blogspot.com/2007/01/google-calendar-sync-for-windows.htmlhttp://www.downloadsquad.com/2008/07/28/calgoo-goes-free-sync-google-calendar-ical-and-others-for-fre/