This year the international code sprint of the Open Source Geospatial Foundation (OSGeo) will take place in parallel to the FOSSGIS conference in Bonn from March 18-25,2018. This is where the core developers of the respective open source GIS projects come together to discuss, plan and develop. Everyone is cordially invited to participate in the days.
The meeting point for the Code Sprint is the BaseCamp, which also offers overnight accommodation.
Interested? Further information and registration for the code sprint can be found here.
If you are looking for accommodation, use the booking portal to enjoy further advantages: http://www.bonn-region.de/events/fossgis.html
Be part of it and help design Open Source GIS software!