

There is the whole thing with Schleswig-Holstein at least. I’m not sure about how far around that is but they are planning to move to an open source stack. I’m also not sure how much money Microsoft will try to throw their way; I doubt they’ll offer to move their German HQ to Kiel.
Plugins and extensions could make sense if the site and plugin are designed to talk to each other. But that could be made safer by each extension being able to decide whether to announce itself (and the user being able to override that).