Gri is an open-source language for scientific graphics programming. Some users consider Gri similar to LaTeX, since both provide extensive power as a reward for tolerating a learning curve. The output is industry-standard PostScript as output, suitable for inclusion in other documents. Gri can make x-y graphs, contour graphs, and image graphs.
Fine control is provided over all aspects of drawing, e.g. line widths, colors, fonts, etc.
Greek letters and mathematical symbols are available in a TeX-like syntax. Folks who write 1000-line Gri scripts usually start with something as simple as the following.