D bindings to clFFT (https://github.com/clMathLibraries/clFFT), an FFT library for opencl.
import clFFT; and the library is ready to go. However, unlike the clFFT C header, you must import your own choice of opencl headers to access the openCL API which is needed for using clFFT. These bindings internally use DerelictCL (https://github.com/MeinMein/DerelictCL and http://code.dlang.org/packages/derelict_extras-opencl) but do not expose it publicly.
To build, simply add the relevant dependancy to your project's dub.json and let dub take care of it and DerelictCL.
If you are not using dub then you're on your own, but something like this should work to create a static library for you to link your project to:
dmd clFFT.d -lib -I$DERELICTCL_SOURCE_DIR -L-L$PATH_TO_DERELICTCL_LIBS -L-lDerelictCL