Cartopolis

Cartopolis is an interactive, networked 3D virtual world that replicates real-world locations using open public data. It offers walkable maps with real-time weather, routing, and public transit information, plus social features like local and private chat, voice communication, and place sharing. Available as a browser-based app, desktop client, and Android app, it is free, open source, and self-hostable, targeting residents, communities, municipalities, planners, and architects.