FFT Lib?

[dsimcha]

I'm going to need an FFT library to perform some convolutions at some point
soon.  Two absolute, non-negotiable requirements are that it be written in
pure D and that it be Boost or compatibly (i.e. zlib or public domain)
licensed.  I also prefer "simple and good enough" over "has every
micro-optimization in the book but a PITA to maintain/modify/use", as long as
it's at least a true fft as opposed to an O(N^2) DFT.  A few questions:

1.  Does anyone already have such a lib?

2.  If noone has one I'll probably either write my own from scratch  or port
some code from C if I can find code that's under a suitable license and
written with a "simple and good enough" philosophy rather than an "every tiny
optimization in the book" philosophy.  Could anyone recommend one to port?

3.  If I do end up writing my own or porting, is there sufficient interest in
this that I should try to target it for std.numerics, or would I be better off
just making it good enough for my use case?