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Chart viewer licences

The chart viewer is the MarineOS chart engine compiled to WebAssembly. It uses the open-source components below. No part of it needs a paid licence.

Qt 6.11.1 (Qt Core, Qt Gui, Qt OpenGL)

Used under the GNU Lesser General Public License, version 3 (LGPL-3.0). Qt is © The Qt Company Ltd and other contributors. The Qt source is available from download.qt.io. As the LGPL allows, you may replace Qt with a modified version: the object files and build instructions needed to relink the viewer are available on request from MarineOS (crpelon@gmail.com) .

Qt bundles FreeType (FreeType License), HarfBuzz (MIT), libpng (libpng License), libjpeg (IJG License) and zlib (zlib License).

Emscripten

The compiler and its runtime libraries: MIT and University of Illinois/NCSA licences (musl libc: MIT; libc++: Apache-2.0 with LLVM exception).

Chart data

• NOAA Electronic Navigational Charts — US Government work, public domain. Converted for display; not an official chart and not for navigation.
• Michigan DNR Inland Lake Contours — State of Michigan open data. Depths measured 1929–1980 and not confirmed by the DNR; not a nautical chart. The DNR and the Michigan Center for Geographic Information assume no liability for its use.
• Natural Earth — public domain.
• OpenStreetMap — place search (marinas, fuel, ramps, restaurants, parks, towns, addresses): © OpenStreetMap contributors, available under the Open Database License (ODbL). The search index is a database derived from it, available on request under the same licence.