bel_fft
FFT co-processor in Verilog based on the KISS FFT
... and the Wishbone bus are supported. However, bel_fft's architecture allows an easy adaptation to further bus architectures (e.g. AMBA AHB). It comes with a Java wizard to configure the co-processor and to generate all required files (e.g. twiddle ROMs).
It comes with integration into Xilinx Vivado, EDK, and Altera QSYS and includes example designs for Xilinx Zynq and with PCI-Express core (including Linux driver and application).
bel_fft is distributed under the GNU Lesser Public License 2.1.