  We want to analyze visually, to what extend team members and external
developers contribute to open-source projects. This gives a high-level
impression about collaboration in that projects. We achieve this by recording
provenance of the development process and use graph drawing on the resulting
provenance graph. Our graph drawings show, which developers are jointly changed
the same files -- and to what extent -- which we show at Germany's COVID-19
exposure notification app 'Corona-Warn-App'.
