Kobo programs

I was wondering what language I have to use to create an utility with a simple GUI for Kobo?
I know Koreader uses lua with Qt but what about KSM or Cool Reader and the other Vlasovsoft utilities?
They too use Qt.
Is it only bash scripts?
I'm not with a computer, so I can't check the files...

I'm using Python 2.x, but I don't suppose it is supported out of the box.
For the GUI I use wxWidgets or Kivy.
Not much luck there also I think.

And do we know what versions of the languages and libraries are supported?

TIA