While all the code in pyfftw (except for fftw3.h) is released under the 3-clause BSD license (set out below), pyfftw requires FFTW3 to function. FFTW3 is available under two licenses, the free GPL and a non-free license that allows it to be used in proprietary programs.
If you intend to use the GPLed FFTW3 library, your code must also be GPL licensed. If you do not wish to comply with the terms of the GPL, you have to buy a FFTW3 license from the copyright holder MIT, see here for more information.
fftw3.h is released under the 2-clause BSD license.
See each file for the copyright holder.
Redistribution and use in source and binary forms, with or without modification, are permitted provided that the following conditions are met:
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