DUST computes the interstellar reddening for a line of sight and/or region of the sky, returning the corresponding 100 micron intensity, reddening maps, region statistics and estimated Galactic extinction. The reddening is derived using the data and technique that Schlegel, Finkbeiner & Davis (1998) pioneered combining the strengths of IRAS and COBE/DIRBE. The user should be aware that the technique is restricted by both spatial resolution limitations and assumptions that are used to derive the dust temperature along the line of sight.