A full-featured Xt widget to display 2D data in a graph. The current version is 1.3.
Source is available at ftp.x.org .
Read this for more info and background on why I moved to this licence. The SciPlot Widget is a widget capable of plotting cartesian or polar graphs, including logarithmic axes in cartesian plots. The widget is subclassed directly from the Core widget class, which means that it does not depend upon any other widget set. Features provided in the widget include automatic scaling, legend drawing, axis labeling, PostScript output, multiple plotted lines, color support, user font specification, dashed lines, symbols drawn at points, logarithmic scales on one or both axes in cartesian plots, and degrees or radians as angles in polar plots. See the demo program information page for compilation instructions and sample programs.