Well, I am making steady progress on my second plugin. I have the isosurface algorithm working and by sleight of hand can specifiy metaballs (i.e. I have to write C++ to say where they are).
Here is my "first light" for a sensible metaball function (as used in POV-Ray).
The link
Facts and figures: Object "metaball", v 104042, s 208080
Steve.