The talk discusses the OSRD project, an open source project developed by the French Railway Company, which aims to map the European railway network using open data. The speaker compares four sources of open data and finds that OpenStreetMap is the best source due to its consistency, high-quality data, and compatibility. They also present an indicator to assess the availability of required and optional data for the OSRD project, which shows that OpenStreetMap is currently the best standard across Europe. The speaker provides detailed analysis for each country and invites interested parties to contact them or learn more about the OSRD project and Open Rail Foundation.