On of the task areas of the German Federal Office for radiation protection (BfS) in an case of a radiological emergency is to collect available and capture own relevant data, process and evaluate these and create documents including the necessary information to enable the crisis unit to make the right decisions for emergency preparedness and response. Some time ago, the BfS started to migrate from a proprietary monolithic system to an approach combining several OSGeo projects into a whole emergency system, including PostGIS, GeoExt, OpenLayers3, Geoserver, GeoNetwork and MapfishPrint and other software even from non-Geo but Open Source projects. To fill missing links between software components and to meet all demands of radiological disaster management, the BfS does not only use Open Source GIS software, but started several own software projects using free licenses as well. To seriously follow the Open Source strategy the BfS started to publish some of its projects using GitHub as a commonly used platform for Open Source projects, but not a common way for a federal office. The talk presents GitHub-driven Open Source projects of the BfS embedded in an OS driven software stack using several well known OSGeo projects.