Scott McMullan: ehick: Calendar Federation and Syndication at UC Berkeley

Jon Udell and others are having a discussion about the sorry state of calendar sharing, both standards activities and clients/platforms (see also Ted Leung and previously Lisa Williams). The particular discussion is centering around Mozilla and Chandler and how to use WebDAV/CalDAV as a transport for calendar sharing. But at the end of his first post, Jon writes:

"I wish there were a middle ground between this model and the dedicated calendar server. Imagine a WebDAV implementation that could map collections not just to whole-file resources, but to XML elements within files. Given an XML flavor of the iCalendar format, you could achieve more finely-granular control over calendar data. But the same model would work for other applications using other XML formats. And you'd have the option of searching with XPath or XQuery, again leveraging infrastructure not bound to any application domain."

He summarizes nicely some of the goals of the Berkeley Campus-Wide Event Calendaring Project, headed up by Allison Bloodworth and others from Berkeley and the CDE. The project was motivated by the fact that there are something like 75 different calendars at Berkeley, and there's no way to easily share events or create user-friendly views or feeds. (BTW their work just won the best presentation/paper award at XML 2004 -- kudos!)

So their focus is to apply Document Engineering techniques to create the XML data model that accomplishes Jon's wishes, and then apply model-based app techniques using XML/XSLT/XSD to create software and glueware to manipulate those events (eg., create calendars). Borrowing from their XML 2004 presentation, they summarize their solution:

A standard XML data model of an Event (Scott says: think UBL for events) http://dream.berkeley.edu/EventCalendar/Events.xsd
A centralized repository of Event information
A calendar management tool

Manage events in the repository
Customize a visually compelling, dynamic web-based calendar

A design for a system architecture allowing XML feeds to and from the repository for calendars who choose to maintain their own website & repository

They have the XSD schemas and have some software built. This is important related work if you're interested in calendar sharing and syndication -- check it out.

[UPDATE:] From Adam Rifkin's excellent Microformats post I found hCalendar:

"hCalendar is a 1:1 mapping of iCalendar to semantic XHTML. ...bloggers often discuss events on their blogs -- upcoming events, writeups of past events, etc. With just a tad bit of structure, bloggers can discuss events in their blog(s) in such a way that spiders and other aggregators can retrieve such events, automatically convert them to iCalendar, and use them in any iCalendar application or service."

This Microformat philosphy is pragmatic == I like!.