Callable from any application that can access a Windows DLL, Prime Factor FFT/32 is a 32-bit Windows 98 and 95/NT version of firm's fast subroutine library for calculating complex forward and inverse FFTs in one and two dimensions. The program provides a tool for developing digital signal processing (DSP) and frequency analysis applications in 32-bit Windows operating systems. Claiming to match or exceed the performance of many DSP boards, the software is hand-optimized and written in assembly language to maximize performance of Pentium floating-point processors. The software includes three FFT types: a prime number-based FFT covers data set sizes with prime number roots of 3, 5, 7, 11, 13, 15, 17 and 19; a Cooley-Tukey FFT covers the power of two data sets; and a discrete Fourier transform analyzes any dataset size not covered by the prime factor or Cooley-Tukey FFTs. In addition, it calculates 2D rectangular FFTs of any shape or size for maximum flexibility in odd-size image processing. Typical applications include shock and vibration testing, applied mechanics, and product testing for quality control.