If you're into that sort of thing, OpenStreetMap supports 3D mapping as well. I haven't looked into it but while from my understanding it's fairly basic, at lea

If you're into that sort of thing, OpenStreetMap supports 3D mapping as well. I haven't looked into it but while from my understanding it's fairly basic, at least you're sure that your data will be around in ten years and openly available for people to use and display.