The majority of KiCad's source code is developed and distributed under the terms of the GPLv3 or later. However, It does include some third-party code licensed under licensed under the BOOST license v1.0, the ISC license and the MIT license. These licenses are compatible, but a combined works as is will be governed under the terms of the GPLv3 (or later). This includes any binary distribution of the KiCad EDA suite by the KiCad project or any third party, e.g. Linux distributor. You are free to use the *sources* under the terms of their respective licenses. Licensed under BOOSTv1: - libcontext [https://github.com/boostorg/context] in thirdparty/libcontext - clipper in thirdparty/clipper Licensed under ISC: - portions of code in include/geometry/polygon_triangulation.h Licensed under MIT: - delaunator in thirdparty/delaunator - tinyspline_lib in thirdparty/tinyspline_lib - nlohmann/json in thirdparty/nlohmann_json - nlohmann/fifo_map in thirdparty/nlohmann_json Licensed under GPLv2 (or later): - dxflib in thirdparty/dxflib_qcad - potrace in thirdparty/potrace - math_for_graphics in thirdparty/other_math - SutherlandHodgmanClipPoly in thirdparty/other_math Licensed under ZLib: - nanosvg in thirdparty/nanosvg Licensed under CC-BY-SA-4.0: - All the demo files provided in demos/* Licensed under GPLv3 (or later): - All remaining code not listed above