Linux

The problem with that is a few years is a bit short to get real benefits out of it. And the Wikipedia article contradicts the statement that productivity went down. Actually issues and errors went down, half the workforce was alright with it and they saved tens of millions of Euros. And then they cancelled it. That decision wasn't backed by technical or factual reasons at all. Many people said they were fine with Linux. Issues were for example that they had old and outdated computers. As a reason to switch back they claimed: sync to mobile phones had issues (...as if government workforce syncs their calendar to their mobile phones...) and these were issues with the groupware suite. Nothing had anything to do with Linux, productivity or the people who sat in front of the computers and actually had to use it. There were quite some benefits and from the technical side things were going well despite admins not being backed by their superiors and the city. They did a final study which contains quite some / mostly dubious statements, and Microsoft also was involved in the switching back.

You CAN enforce a change. Sure, change is always hard in the beginning. But we do it all the time. The story of LiMux is more: You can destroy anything if you really want to. And politics likes to twist things so it suites their narrative. (And lobbyism is a thing and Microsoft is better at it than the Linux community.)