MathMod

MathMod is a portable interactive plotting and graphing program for Windows, Linux, MacOSX and many other platforms.
MathMod allows to plot 3D mathematical surfaces, described by implicit or parametric equations, and offers a very large database of model samples that can be generated with it. It's Free and Open Source.

Change-log for MathMod-11.1 (16/06/2021)
Welcome to the realm of complex numbers!

1) Support of graphing functions with complex numbers Z=u+iv in 3D and 4D spaces (demo scripts: "Complex3D_xx" and "Complex4D_Saddle")
2) Added support for HSV (hue, saturation, lightness) coloring model (script: "Complex_Domain_Coloring")
3) Texture definitions (RGB and HSV) for parametric surfaces can now be expressed as functions of complex numbers
4) Added a software implementation for the OpenGL variable gl_FrontFacing (fixed an issue with GPU drivers on MacOSX Catalina).
The activation of this patch is available from mathmodconfig.js ("OpenGlConfig"-->"GL_FrontFacingSup