View this article at: http://www.macnn.com/articles/08/12/02/google.calendar.and.ical/
Tuesday, Dec 02, 2008 9:45am
Google adds iCal support to Calendar
Google has officially announced public support for the CalDAV protocol in Calendar, its online scheduling application. The update means that Mac owners can now integrate Calendar with iCal, which in turn should allow sync between the two programs, the ability to operate offline, and answer invitations from other users. It should also be possible to track the free/busy information of colleagues.

The CalDAV hooks have been in testing with developers since July, according to Google, and this has allowed them to write a setup utility for iCal. The app is said to automate the process of linking information with Calendar, and is a free, open-source download via Google Code. Its availability will likely mean the integration of Calendar support into a host of third-party software.