GroupDAV was an effort to create a "down-to-the-earth" protocol to connect OpenSource groupware clients with OpenSource groupware servers. By the means of reusing the iCalendar (RFC 5545) and vCard (RFC 2425) formats to represent data, and the WebDAV (RFC 4918) protocol to retrieve records and apply changes.
A major goal of GroupDAV was to keep the protocol as simple as possible and to stay focused on real world issues with OpenSource and free software applications.
Unfortunately, though, this didn't completely fly ;-)
More precisely, GroupDAV got superseded by CalDAV (RFC 4791) and CardDAV (soon to be an RFC). In fact the basic idea of using iCalendar and vCard on top of WebDAV turned out to be a great success with a lot of support from even the largest companies, Apple, Google, Oracle, Sun, Yahoo, Zimbra but also from a lot of small companies, say Kerio, Zarafa, or OpenSource projects like ScalableOGo, DAViCal, Bedework or Mozilla Lightning.
CalDAV and CardDAV are more complex, but apparently people want that - just check the list of implementors :-)
The CalDAV/CardDAV development is driven by the CalConnect consortium. Everyone is welcome to join!
Helge did a talk on CalDAV/GroupDAV at FOSDEM, you can grab the Video over here: CalDAV - the open groupware protocol
From the early stages of GroupDAV: Cornelius Schumacher interviewed
KDE Kontact guru Cornelius Schumacher got interviewed during the Dutch KDE-PIM meeting. The interview contains a nice introduction into the motivations of GroupDAV and why it doesn't conflict with CalDAV [read it!]. Cornelius was part of the KDE team that joined with participants of OGo to create the first version of the draft.
The Draft (deprecated)
The draft-01 is the very first version of the draft. It has a set of issues which need to get resolved - we will need some iterations until this is a sound document.
Be sure that you understand the limited scope of this effort prior drawing incorrect conclusions. You are invited to join our mailing list to ask any question you have.
So what is it about?
GroupDAV had a very specific focus which is connecting the three popular OpenSource clients - Kontact, Evolution and Sunbird - with the broad range of OpenSource "groupware" servers. Whatever "groupware" means to the ~200 projects listed on Freshmeat.
This is a very specific focus because all the three clients have no legacy issues and are 100% iCalendar based while the far majority of the OpenSource servers started as RDBMS web applications which did not care about iCalendar at all.
Our goal was to connect them to native clients in a useful way despite their legacy issues. As an example consider the Bugzilla bugtracking system to expose its bugs as iCalendar tasks. Bugzilla can't represent a recurring task in the iCalendar concept nor does it feature alarms.
GroupDAV is supposed to deal with such setups in a graceful and pragmatic way.