Hi folks,
This summer, i have implemented some addons for the calender that support among other things upload and download of calendars in the ical format, as well as providing shared calendars via webdav (when webdav writes an ical file, it is parsed on the fly, when ical reads in ical file, it is generated on the fly).
i have tested the code with mac os x ICAL and Mozilla calendar (sunbird, thunderbird cal, firefox cal). Synchronization works only with the mozilla family. ICAL unfortunately rewrites calendar item-ids after upload, one can publish ICAL calendars based on the code. Bulk download seems to work as well with the microsoft calendar. We are using this code now on our production site.
Since the code is implemented using xotcl, i am somewhat reluctant to check it into cvs just now. Currently i am doing some more polishing on the xotcl-core stuff (improved reloading) and will upload xotcl into CVS head as soon xotcl 1.3.7 is out.
For now, the calendar with ical support is here,
http://media.wu-wien.ac.at/download/acs-api-documentation-procs.patch
it works with xotcl 1.3.6 as described in
https://openacs.org/forums/message-view?message_id=316806
