An easy scientific data visualization widget for the FLTK library. The widget is an OpenGL based contour visualizer for Linux, which allow you to built 2D and 3D graph of contour and colour map for a xy regular or scattered data set. There is a good example with the topographic data of Poland with 5902 data points to introduce yourself how to use it. There is not much documentation but it is easy to use. The input data are in XYZ format, where Z is a function of XY of the form Z=F(X,Y). The data file is in plain text format.