Foss4g NL: late afternoon sessions (web components + railway API + long-living data)

(One of my summaries of the 2026 one-day Foss4g open source geo conference in Groningen, NL). Railmaps: Prorail open source GIS viewer based on generic web components (GeoBlocks) Warning : the title mentioned it as an open source GIS viewer, but it is not open source . After the presentation I asked where I could find it, but they said it was internal-only. They used open source, but the project…