Cf. "The rise and fall of Limux" (2017) https://lwn.net/Articles/737818/
Initiated by the city of Munich, LiMux aimed to migrate public administration systems from Windows to a Linux-based OS to increase control over IT infrastructure and reduce costs. Despite initial success (announced at LinuxTag in 2014, I was there for the announcement), the project faced intense political lobbying by Microsoft leading to a reversion to Windows.
More examples in this note: https://lab.abilian.com/Tech/Linux/Sovereign%20OS%20-%20%22E... (in particular https://lab.abilian.com/Tech/Linux/Sovereign%20OS%20-%20%22E...)
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