Until 1.0.6 the Europe, World, Britannia and Black Sea maps came from the OpenFront map generator (CC BY-SA 4.0); since 1.0.6 every map here is built from public data. The World, Europe, Black Sea and Britannia maps (world/, europe/, blacksea/, britannia/) were rebuilt for Front+ 1.0.6 from public data in place of the OpenFront maps of the same name; only their size, the shape they were fitted to and their nations' names, flags and spawn places come from those maps: * Relief and coastlines: ETOPO 2022 Global Relief Model (15 arc-second tiles; the World the 60 arc-second global file), NOAA National Centers for Environmental Information, public domain. Cite as: NOAA National Centers for Environmental Information. 2022: ETOPO 2022 15 Arc-Second Global Relief Model. NOAA National Centers for Environmental Information. DOI: 10.25921/fd45-gt74. ETOPO 2022's land elevation is built from, among others, Copernicus DEM, which NOAA credits as: The European Space Agency. Copernicus DEM - Global and European Digital Elevation Model (COP-DEM); and FABDEM (Hawker et al. 2022, Environmental Research Letters 17(2), 024016). * Land, lakes and rivers: Natural Earth 1:10m vectors, public domain (https://www.naturalearthdata.com, "Made with Natural Earth"). * climate.bin: the Koppen-Geiger climate of Beck et al. 2018, CC BY 4.0 (the paragraph on climate.bin below). Each of these folders has a SOURCES.txt with the exact files, projection, latitude range and where every nation's spawn comes from. The Switzerland map (switzerland/) is built from the Swiss federal geodata of the Federal Office of Topography swisstopo (https://data.geo.admin.ch), free to use with attribution: (c) Bundesamt fuer Landestopografie swisstopo. Its SOURCES.txt names every dataset and the neighbours' elevation models that swissALTI Regio merges. The Switzerland and its neighbours map (switzerlandneighbours/, Front+ 1.0.7) is built from the same swisstopo data, (c) Bundesamt fuer Landestopografie swisstopo, with the foreign elevation models swissALTI Regio merges (named in its SOURCES.txt) and Natural Earth 1:10m admin-0 for the lines between France, Germany, Italy and Austria, public domain ("Made with Natural Earth"). The Greece, Yugoslavia, USA and Egypt maps (greece/, yugoslavia/, usa/, egypt/) were built for this game from public data, not from the OpenFront generator: * Borders, regions, lakes and spawn towns: Natural Earth 1:10m vectors, public domain (https://www.naturalearthdata.com, "Made with Natural Earth"). * Relief and coastlines: AWS Open Data Terrain Tiles (https://registry.opendata.aws/terrain-tiles/), which credit: SRTM and GMTED2010 terrain data courtesy of the U.S. Geological Survey; Global ETOPO1 terrain data U.S. National Oceanic and Atmospheric Administration; Europe terrain data produced using Copernicus data and information funded by the European Union - EU-DEM layers (Greece and Yugoslavia). Each of these folders has a SOURCES.txt with the exact layers, projection, latitude range and where every nation's spawn comes from. The climate.bin in every map folder (Switzerland, Switzerland and its neighbours, Greece, Yugoslavia, USA, Egypt, Black Sea, Britannia, Europe and World: each map's moisture, which draws its deserts, steppes, grass and forest) is derived from: Beck, H.E., N.E. Zimmermann, T.R. McVicar, N. Vergopolan, A. Berg, E.F. Wood: Present and future Koppen-Geiger climate classification maps at 1-km resolution, Scientific Data 5, 180214 (2018), doi:10.1038/sdata.2018.214; data doi:10.6084/m9.figshare.6396959. Licensed CC BY 4.0 (https://creativecommons.org/licenses/by/4.0/); attribution required. Changed: the climate classes were turned into moisture values, reprojected onto each map's grid and smoothed (the Climate section of each SOURCES.txt gives the table and the method). The land's real colours in every map folder (colour.jpg or colour.png; the game draws them under its own light and relief while the Realistic look is on) come from two sources; the Colour section of each SOURCES.txt says which, and how: The colour.jpg of the Greece, Yugoslavia, Egypt, Britannia, Black Sea, Europe and USA maps (greece/, yugoslavia/, egypt/, britannia/, blacksea/, europe/, usa/; since Front+ 1.0.9, one colour a tile) and of the two Swiss maps, Switzerland and Switzerland and its neighbours (switzerland/, switzerlandneighbours/; since Front+ 1.0.9, two colours a tile, Switzerland the same on both) is derived from the ESA WorldCover Sentinel-2 median L2A (RGBNIR) composite of 2021, v200, by the ESA WorldCover project, its red, green and blue bands, read from the open-data bucket https://esa-worldcover-s2.s3.eu-central-1.amazonaws.com/ (terms: https://esa-worldcover.org/en/data-access). Licensed CC BY 4.0 (https://creativecommons.org/licenses/by/4.0/); attribution: © ESA WorldCover project / Contains modified Copernicus Sentinel data (2021) processed by ESA WorldCover consortium Changed: reprojected onto each map's grid and area-averaged, its water and the land's no-data left out and filled from the land round them, the tone mapped from reflectance to colour. The colour.jpg of the World map (world/; since Front+ 1.0.9 on the full grid) is derived from NASA's Blue Marble Next Generation (Reto Stockli, NASA Earth Observatory; 500 m, 2004), public domain (NASA imagery is not copyrighted; credit: NASA Earth Observatory), fetched as tiles of the WMTS layer BlueMarble_NextGeneration from NASA's Global Imagery Browse Services (https://gibs.earthdata.nasa.gov). We acknowledge the use of imagery provided by services from NASA's Global Imagery Browse Services (GIBS), part of NASA's Earth Science Data and Information System (ESDIS). Changed: reprojected onto the map's grid, its water left out and filled from the nearest land. (Egypt's colours were Blue Marble's from 28 September 2026 to Front+ 1.0.8, the other maps' in Front+ 1.0.8.) Egypt's Lake Nasser is SRTM's flattened water surface from the same AWS Terrain Tiles as its relief.