Super Mongo(SM) is a plotting program written by Robert Lupton and Patricia Monger.

Its virtues include the fact that it treats input data in vector form, this makes operations on the data transparent. When you start SM you are faced with a command line interpreter and the functions available are flexible and pwerful. If your name is John the command line will say

Hello John, please give me a command
If you feed it junk it will tell you
I'm sorry John, but I can't help you with that
The icon for the program is composed of a ball and chain.

On the downside it is not free, but it's pretty free. The documentation sucks. The manual that I am currently looking at from 1992 has this to say SM is still evolving slowly, and this documentation may not be true, helpful, or complete. In order of increasing plausibility, information may be obtained from this document, the HELP command, the authors, and the source code.