With iCal: Does this let FileMaker sync with iCal?
Even Better: This makes FileMaker Server into an iCal Server. So you can read, edit, create, and delete FileMaker records from within iCal or from any iCal compatible client (like the calendar on your iPhone).
You're actually reading and writing to FileMaker Server, so we're not really synchronizing: if you edit an appointment in iCal or on your iPhone, it is edited in FileMaker right then.
And when someone edits an appointment in FileMaker, you'll see it in iCal (or on your iPhone) as soon as you refresh the calendar. (Both iCal and the phone's calendar refresh automatically every so often, for information on how to control the frequency of this refresh, check here.)
With Google: How does Zulu sync with Google Calendar and Contacts?
Zulu maintains a sync database for each Google - FileMaker account pairing and syncs the two databases as often as you'd like: manually or according to a frequency set when you configure your sync (we recommend every 5, 10, or 30 seconds).
You don't have to run any FileMaker scripts to get this working: the sync is handled within Zulu, all you have to do is pair a FileMaker account with one or more Google accounts and set your sync frequency.
The sync rules are simple, the last edit wins, so if a FileMaker user and a Google user edits the same event, whomever edits that event last (ie most recently) wins. Google handles multiple Google users editing the same event, and FileMaker handles multiple FileMaker users editing the same event.
Can I use the iCal services and sync to Google Calendar at the same time?
Yes. iCal appears to Zulu like another FileMaker user so it makes no difference to the Google sync if some of your users are editing records in iCal, some in FileMaker, and some in Google.