It is no secret that the french state agencies make a wide use of Free Software. In a live example of government sent email headers:

X-Mailer: MIME::Lite::HTML 1.21

Showing the use of the MIME::Lite::HTML perl package.

They don't appear to be upgrading their software on a daily basis though: v1.21 actually dates back to 2004, v1.23 is now the current version and was released in 2008.