Miriam Goldberg wrote:
> I'd go with icalendar. It plays nicely with most major calendar applications.
> 
> also, at the risk of sounding like a shill, I'm helping develop a web
> app (www.fusecal.com) that'll make it easier for web publishers to get
> their calendar information into users personal calendars and keep the
> information up to date as the calendar changes.

I'd also take a look at Bedework (http://www.bedework.org)

The problem that I have with Calendar systems is not technical but a 
social issue.  We've got several calendar systems at our campus, but 
other than the Oracle Calendar system that is used to schedule meetings 
I don't use them.

The problem is that, in the case of events, while the person responsible 
to announcing the event might put it into a calendar, they also try to 
advertise the event as far and wide as possible so they post a notice to 
all of the relevant mailing lists that they can think of.  Since I'm on 
a lot of mailing lists, I might get 5-6 copies of an announcement of an 
event I have no desire in attending, then get reminders on those same 
list a few days prior to the event.  Then there may be someone reading a 
mailing list, see the announcement and think that it should be forwarded 
to another mailing list they read (which I'm also on) so I get more 
copies of the event announcement in my email inbox.   Unless it's 
mandated by an institution that events and other calendar related 
announcements should *only* go on the institutional calendaring system 
and not be distributed on mailing lists there really is no point in 
consuming calendar events from the calendaring system if I'm just going 
to get them pushed into my email inbox anyway.