OpenMapTiles is an open-source stack for building vector-tile maps from OpenStreetMap data. It consists of a tile schema, ready-to-use map styles and tools that generate the tiles. Developers and GIS teams can run the stack on their own servers or in an offline environment and display the resulting map in their own applications. The project was created by MapTiler and is maintained by the MapTiler team together with contributors; its code sits in the openmaptiles organisation on GitHub.
MapTiler AG, the company behind the project, is based in Unterägeri, Switzerland, according to its website. The code is released under the BSD 3-Clause licence and the cartographic design under CC-BY 4.0, so an organisation can use and modify the stack without a vendor contract. Where the data is stored depends on where you deploy the tiles. MapTiler's separate commercial service, MapTiler Cloud, runs from data centres in Western Europe, North America and Asia. For a European organisation, a self-run installation keeps the map data under its own control, while the hosted service is a separate contract.