DotPlot is an Eclipse plug-in to graphically compare word sequences of any type of text. Matches will be plotted as dots on a graph. Similarities in thousands of lines of text or code will result in typical textures and diagonals in the plot.
Here you see the main window divided in three parts.
Configuration dialog to change the color of the Dotlot.
Your dotplot could look like this.
Configuration dialog of the Grid feature of Dotplot.
In the Navigator you select files and folders for plotting.