jones_supa writes: France's National Gendarmerie — the national law enforcement agency — is now running 37,000 desktop PCs with a custom distribution of Linux, and by summer of 2014, the agency plans to switch over all 72,000 of its desktop machines. The agency claims that the TCO of open source software is about 40 percent less than proprietary software from Microsoft, referring to their article published by EU's Interoperability Solutions for Public Administrations. Initially Gendarmerie has moved to Windows versions of cross-platform OSS applications such as OpenOffice, Firefox, and Thunderbird. Now they are completing the process by changing the OS. This is one of the largest known government deployments of Linux on the desktop.