Dr. Bernstein, I've copied the scipy-dev list on this mail. We develop an Open Source (BSD style) package of scientific computing modules for Python at www.scipy.org. We've been using fftpack and, optionally fftw, for our fft module. fftw's license is GPL, otherwise we would be using it as the standard package. One of the community developers (Pearu Peterson) has been working hard on improving the fft module lately and ran across your fft package. Congrats on making such a nice tool. Combining your algorithms for power of 2 and fftpack's generic length ffts provides pretty much equivalent or better performance than fftw on most fft lengths. Pearu posted benchmarks below: http://www.scipy.org/site_content/mailman?fn=scipy-dev/2002-August/00110 1.html I searched for a license in the djbfft source but didn't see one. I also didn't see any mention of djbfft on http://cr.yp.to/distributors.html. So, the question is, can we include djbfft source code in SciPy and distribute it under its BSD license? The SciPy community is certainly willing to contribute every change we make to the source code. Our changes are typically made to help with compatibility across platforms and only occasionally to the core algorithms. Thanks for making your tools available on the web, and I look forward to your reply regarding the licensing issue. Regards, eric