Description:

mathplot is a GUI frontend for interactive graphing of
functions. mathplot2ps is a batch program to generate
PostScript output.

You can have both equations (y=f(x) or f(x,y)=g(x)) and
inequations. For inequations, mathplot hatches the inter-
section. For example, with y>0, y<x and x<2 it hatches the
solution which is a triangle.
You can name a point, anywhere or on a function. You can
ask for the tangent of a function.
As it uses a symbolic library, you can enter functions
like "x+1/y=2".
Can find root (zeros), extrema (even symbolically, some-
times) and intersection of 2 functions.
mathplot exports in PostScript so that you can print eas-
ily, and with the reference mark (O, i, j).
You can save and load files. mathplot2ps can transform
these files into PostScript.
It's written in OCaml using the Tk toolkit for the GUI
frontend