The organisers of this have asked me to pass on to people interested in OpenGuides that we are welcome to come to this event. They don't currently have anyone from OpenGuides or the UK.
The event is on September 25th to 27th (so quite soon) in Furtwangen, Germany. Unfortunately I won't be able to make it, but feel free to go along instead. More information is available from their web site at:
openguides-dev@lists.openguides.org