The resample program "resamples" a soundfile to change its sampling rate. For example, it can be used to convert the sampling rate from 48 kHz (used by DAT machines) to 44.1 kHz (the standard sampling rate for Compact Discs).

The windowfilter program designs Finite-Impulse-Response (FIR) digital filters by the so-called "window method." In this method, the ideal impulse response (a sinc function) is "windowed" by a Kaiser window (a popular window used in spectrum analysis).