I see references all over the web alleging that the commercial Quanta Gold is an enhanced and expanded version of the free Quanta Plus. I can't find anything indicating what the actual differences are apart from the fact that Quanta Gold has a Windows version.
I asked the developers of Quanta Gold and got this:
"the same guys who wrote Q+ originally wrote QG and did it from scratch having learned from their mistakes. The program scales much bigger with no performance issues for one, but it's been years since I've looked at Q+, so I can't really give you a side by side."
Which is faint praise for their own product. I'm not about to hand over the money without knowing what I'm getting. I'm astounded that the developers can't give a straight answer.
Can anyone shed some light?