Yes, that was Munich with its LiMux project.

Incidentally and possibly unrelated, the project was abandoned after Microsoft moved their headquarters back into Munich.

It was Munich, the project was called Linux. Their previous mayor (Ude, social democrat) started the Linux project. The next mayor, Reiter, also a social democrat, even called himself a Microsoft fan and cancelled it against all advice. Suddenly Microsoft moved their Germany headquarters from a suburb to the city, so you go figure. Also, there were some internal power struggles between departments and some obvious mismanagement. Conservatives always have supported Microsoft, and the G, as usual, had no clue about tech and first supported Microsoft, but now claim to always have supported open source... Total shitshow.