Question about successful programs written in C++

[Aziz as]

Hello all,
I have a question about successful c++ product like Adobe Photoshop , Acrobat.
We see that all of these products were written in C++ , but i do not know how these product program the Graphical interface ?
I do not think they used Qt because i read about them in Wikipedia , and they did not mention Qt at all.
Thank you in advance.