DPlot is a general purpose graphing program designed for scientists, engineers, and students. It features multiple scaling types, including linear, logarithmic, and probability scales, as well as several special purpose plots: tripartite grids (shock spectra), grain size distribution plots, polar plots, contour plots of 3D data, and box-and-whisker plots and dot graphs of one or more 1D samples. Manipulation/analysis functions include FFT, filtering, curve fitting and smoothing. Data can be input via a variety of file formats, copied from the clipboard, sent to DPlot from another program via dynamic data exchange, or generated by formula. Source code for example Visual Basic and C demo driver programs are included.