My comment is in thre parts:

1. My SS will be 5346 for ever on XP. If my actual XP burns
I have alternatives: another XP Home, another XP Pro. and one Millenium.
An acceptable alternative could be some updated Plugin installable on 5346.

2. The "dead stone Maxima" is not worth a comment. If it's not possible to
copy paste the Handbook demo and adapt to other stuff: Draw3D => recycle bin.

3. "Crappy 3D Maxima" speaks by itself:
No user mesh density in both X/Y directions.
No user mesh color. The actual default gradient color is non-sense.
The "non-sense gradient color" is blind to color blind person(s) and
"3D flat person(s)".
In short: 3D Maxima is not even pregnant of the 3D first essentials.

Works for me even with the most recent SMath version.

"do as much as possible" is a very individual thing. Does it include using a clean SMath with Maxima portable installation?

Please note:

The plot shown by Jean is a 3D Plot Region provided by the 3D plot plugin. It is NOT related to Maxima.

That's right: NOT a Maxima, just a plot region like X_Y
In fact, it is NOT a 3D, simply a 2D parametric.
The function in "Draw3D" is misleading: it is a symmetric
Gaussian. Levels are pure circles.
The attached demonstrates some useful "contour" tips.

Thanks Martin.

Contiur QUICK.sm (24 KiB) downloaded 70 time(s).