GUI with embeded OpenGL window for commercial use


Hello guys, I am about to create an OpenGL render engine in C++ and want to integrate it into a GUI window to provide buttons, etc. for interaction. The project should be oriented to get commercial in the future. In the past, I had used in my BSc thesis Qt to create such a project and I found it awesome. Unfortunately, Qt is for commercial use very expensive and so it is not an option for me. After searching a while I found this site:, which lists the most available GUI toolkits which can be used with OpenGL. After reading this article I found that GTK+ and wxWindows are the best alternatives to Qt and are cross-platform, too. So I would be appreciated if you could tell me your experience and what GUI framework you believe is the best alternative to create commercial apps.