Credits and Licences

Last updated: 2026-10-08

Map data

• Base map: © OpenStreetMap contributors, available under the Open Database Licence (ODbL). Vector tiles from OpenFreeMap in the OpenMapTiles schema.
• Terrain: elevation tiles from the Terrain Tiles on AWS open data set (for this region, SRTM and GMTED2010).
• Offline relief: ETOPO1, NOAA National Centers for Environmental Information (public domain).

Software

Built with open source libraries, including MapLibre GL JS (BSD-3-Clause), OpenLayers (BSD-2-Clause), PMTiles (BSD-3-Clause) and React (MIT), each under its own licence.

The game is based on Open Historia, © Nicholas Krol and contributors, licensed under the GNU Affero General Public Licence, version 3 or later. We have modified it. The source code of the version we run is available at [HELMI_SOURCE_URL not set]. This notice is removed when the game no longer contains Open Historia code (set HELMI_UPSTREAM_REMOVED=1).