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 graphs: 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 functions include FFT, filtering, and smoothing. Data can be input via file, copied from the clipboard, generated by an equation within DPlot, sent to DPlot from Excel via the supplied Add-In, or sent to DPlot via dynamic data exchange. Source code for example Visual Basic and C demo driver programs are included.