I Cal
These are the docs for our FM10/11 version of the Pro Calendar. Docs for the newer, FM12 version of our calendar can be found here.
Can I show iCal records IN the calendar?
Yes. The calendar can show iCal data sources along side FileMaker records. Learn more here: Multiple Sources
Exporting to iCal
The Pro calendar includes support for exporting found sets of events to the iCal format. You'll find a button in the upper right of the Event List layout that will export the found set as an .ics file to your desktop. This script takes a source number as a parameter so you can export any of your FileMaker sources to iCal.
Here are some tips to help you get the most out of this:
Troubleshooting the iCal Export
The iCal export requires an xsl file in the Extras folder that came with SeedCode Complete.
This xsl file can be placed almost anywhere you'd like-- provided you tell the script "Export Found Set to iCal { SourceNumber }" where to find it. If you're serving the calendar you can even put the file on a web server, so everyone has the same path to it, and the give the script the file's URL.
Here's how. Edit the script "Export Found Set to iCal { SourceNumber }" and find the "Export Records" step. Click "specify" next to Specify output file. When the next screen comes up click OK and you'll be on a screen called "Specify XML and XSLT options". Select HTTP Request, and enter the URL of the seedcodeiCalExport.xsl file. Or leave the setting on "file" if you're not using a server and just find the seedcodeiCalExport.xsl file on your machine.
More recent techniques
XSLT export has be end-of-lifed by FileMaker. An easier way to get your data out to iCal is to use SeedCode Subscribe and publish your events as read only Calendars. (Requires FileMaker Server 12 or higher.) This is very easy to set up and, unlike xslt, very easy to modify.