Since version 5.1, Meso-NH is freely available under CeCILL-C license agreement. See LICENSE.txt, CeCILL-C_V1-en.txt (English) and CeCILL-C_V1-fr.txt (French) for more information. However some parts of the Meso-NH web site are still subject to a licence agreement for a while.
Meso-NH Mail List
Météo-France maintains a Meso-NH mail list, to which anyone can subscribe and unsubscribe. It is used for Meso-NH official announcements, releases and updates. To subscribe/unsubscribe to the Meso-NH mail list, send an email to <jeanine.payart AT meteo.fr>
Access to operational analyses
If you want to access to operational meteorological fields to initialize Meso-NH simulations, you have a choice of two sources: Météo-France and ECMWF. The authorization process is slightly different.
Access to ECMWF data: For French users, follow the instructions given in the document (requestECMWF_v2014.doc). The ECMWF authorization will need the agreement of your National Weather Service, so the full process may take some time. (You need also a valid USER, SECURID-card, and a workstation declared at ECMWF.)