@neuehier, although not 1:1, wxWidgets is usable for EFI GUIs (I've a LINX 1010 with one), and it can delegate to wxQt when required. I can't imagine a situation in which you'd run the preboot application outside of a preboot environment, though, so, in practice, it wouldn't delegate to it frequently. If you needed the application to be versatile enough to be able to operate in both environments, though, it'd work.