  This article describes the FFTJet software package designed to perform jet
reconstruction in the analysis of high energy physics experimental data. A
two-stage approach is adopted in which pattern recognition is performed first,
utilizing multiresolution filtering techniques in the frequency domain. Jet
energy reconstruction follows, conditional upon the choice of signal topology.
The method is efficient, global, collinear and infrared safe, and allows the
user to identify and avoid the event topology bifurcation points when energy
reconstruction is performed.
