SeedCode has released an iCal server for FileMaker, Zulu (http://www.seedcode.com/zulu), a collaboration with the developers at 360Works. Zulu is a server-side plugin for FileMaker Server that lets iCal see your FileMaker data as iCal calendars.
You can edit your records in iCal and from the calendars on your iPhone and iPad. When you do, you’re editing the FileMaker records directly. iCal will even respect FileMaker’s record locking if someone else is editing the record when you try to do the same.
You can show your FileMaker data as another calendar in iCal. Zulu filters allow you to publish just part of a FileMaker table or publish a single table as more than one calendar. Zulu respects FileMaker access privileges and record locking. You can optionally run post-edit and pre-delete scripts in FileMaker when changing records in iCal.
Changes made in iCal, iPhone, or iPad are instantly visible in FileMaker Pro. Also, changes made in FileMaker are visible in iCal as soon as iCal refreshes. Zulu requires FileMaker Server 9 or higher
Pricing starts at US$299 for a workgroup license that offers up to five calendars to any number of users.