Quote: "I've been reading up on 2.0 which the author has apparently disappeared."
I think it is tweakable enough that you can work with it yourself. Some key parts are delegated to a non-open source part (compiled into the gdkengine.dll) however. This mainly goes for the aspects in which it differs from DarkBASIC such as with the 3D math. It is however entirely possible to create wrappers for the original DBPro functions in the parts where those new variants are broken (mainly the shader data transfer functions).
The big question is whether the license
actually let's you sell or even publicize what you are developing - the gdkengine.dll, which essentially is what you are paying for, must be supplied with your application and then it can be "stolen" by anyone using the "free" GDK2 version.
"Why do programmers get Halloween and Christmas mixed up?" Because Oct(31) = Dec(25)