Open Data Nantes Métropole: A Catalogue Where Every Dataset Carries a Licence

Nantes opened its data portal in 2011 — by its own account the sixth French local authority to do so — and later merged it into a platform shared with the Loire-Atlantique department and the Pays de la Loire region, so the same catalogue is reachable under three domains. On 10 August 2026 it held 589 datasets and every one of them carried an open licence: 544 under the Licence Ouverte, 43 under the Open Database Licence, and two under later Licence Ouverte variants. Twenty publishers account for 588 of them; the Ville de Nantes (263) and Nantes Métropole (256) dominate, but the transport operator Semitan, the regional air-quality association Air Pays de la Loire, JCDecaux, the car-share operator Citiz and the cycling association Place au vélo all publish under their own names. The catalogue carries working series rather than only registers — hourly car-park occupancy back to 2010, daily cycle counts, and the electromagnetic-field observatory.