Le site a été créé avec le service Drupal Gardens (Drupal 7)
[Update 2016] Drupalgardens announced to its client that the service closes. Among all possible reasons for this, I retain the migration issue: migrating all those websites from Drupal 7 to Drupal 8 would be quite a challenge and is not the remit of such a Software as a service. The positive aspect is that each website is easy to archive / export and install on another hosting, Drupal 7 being still there for a while.
Drupal is a now famous open source content management. Easy to install, Drupal offers all the necessary functionalities (with a very strong taxonomy system), but also a lot of extensions through third party modules.
Recently, the latest barrier to offer Drupal to the masses has disappeared: Drupalgardens allows people without hosting to create a Drupal site for free, in a couple of seconds.