Discussion: These two use cases proved the feasibility of opening public health data on the internet, and highlighted difficulties: SDMX, a full-featured solution, encouraged harmonization and reusability, sustainability, but required complex developments and tools; OData was much simpler to implement but required a “from scratch” description and did not encourage reusability. From an end-user perspective, integration in every-day tools is not achieved yet. These two approaches are a first step to interoperability in PHS. (Source: International Journal of Medical Informatics).