PLplot is a library of C functions that are useful for making scientific plots from programs written in a wide variety of languages. It can be used to create standard x-y plots, semi-log plots, log-log plots, contour plots, 3D plots, shade (gray-scale and color) plots, mesh plots, bar charts, and pie charts. Multiple graphs may be placed on a single page with multiple lines in each graph. Different line styles, widths, and colors are supported. A virtually infinite number of distinct area fill patterns may be used. A variety of output devices and file formats are supported.
Cactus is a general, modular, parallel environment for solving systems of partial differential equations. The code has been developed over many years by a large international collaboration of numerical relativity and computational science research groups and can be used to provide a portable platform for solving any system of partial differential equations.