Mandelbrot
Mandelbrot figures are created by an algorithm using complex numbers.
The following formula is repeated until z exceeds a certain value. The number of times the formula is used determines the color on point (x0, y0).

z0 = x0+iy0;
N= 0;
z = z0;
while ((|z|<2)&&(N>Nmax))
{ N++; z = z*z +z0; }
Color = N;

I modified the system a little:
z0 = x0+iy0;
N= 0;
z = z0;
while ((|z|<2)&&(N>Nmax))
{ N++; z = z*z +z0 + C*z; }
if (|z|<2.0) Color = N;
else Color = N + 4/(|z|*|z|)

By changing "C" you can modify the formula. The last line makes an interpolation between integers. Color needs to be a real now.

You can download the program "Mandelbrot.exe". The parameters that have created the following pictures are stored in files "*.KYK", and can be downloaded by clicking on the pictures.
This program allows you to zoom in and out, change viewing angle, add height to it, select the size, change the colors, magnify it, store and load the parameters, store the picture.
Mind the fact that the size of the picture is not stored in the parameter file.
A list of functions is given in the menu item "help".
When starting the program, accept the initial values of the dialog box.

 Curly_1 Curly_2 Star2 Spiral_6 Spiral_5 Spiral_7 M2Wad4 Snow_3