When the open source email client Thunderbird was released this week there was a fair chunk of code which was developed by the French military.

France's military chose open source software after an internal government debate that began in 2003 and culminated in a November 6, 2007, directive requiring state agencies "Seek maximum technological and commercial independence." The military used Mozilla's open source design to build security extensions, while Microsoft's secret, proprietary software allowed no tinkering.

Lieutenant-Colonel Frederic Suel of the Ministry of Defence and one of those in charge of the project said that although it started as a military project, it was quickly generalised it. The Gendarmerie Nationale police, which was part of the military at the time and did the design, released some of its work to the public under the name "TrustedBird," and co-branded it with Mozilla.

The military uses Mozilla's Thunderbird mail software and in some cases the Trustedbird extension on 80,000 computers it is also used in lots of other government departments. Thunderbird 3 used some of the code from TrustedBird mostly to allow them to know for sure when messages have been read.

David Ascher, chief executive of Mozilla Messaging said that the extension qualifies it for NATO's closed messaging system, and the French military has shown TrustedBird to NATO. The French military is also helping build an ecosystem of specialists around the world that provide specialised add-ons. They have done quite well. The result is compatible with Yahoo! mail, Google Gmail and other email systems, but competes against Microsoft Outlook.