Are you as tired as I am from people bringing up Munich’s Linux phase as a bad example?
Well, the European Commission's Open Source Observatory released a case study that comprehensively tells the whole story.
Instead of just sharing it like a reasonable person would I went full Charlie Day in a blogpost about how it applies to Open Source in Public Administration efforts today: https://tarakiyee.com/lets-talk-about-open-source-in-munich-and-everywhere-else/