I need to develop an application for Windows, Linux and Mac. To not have to write all the window cruft myself I chose to use Qt5 (over wxWidgets, because the latter ship no precompiled binaries). I have a GTK Widget (of Cef) which I now need to embed, but sadly have no idea how.
There seems to have been QX11EmbedContainer in previous versions of Qt, but it is not present anymore and also I am not sure this works, when there is a switch to Weyland.
You can try the QT WebKit if you need just a embed browser
http://qt-project.org/doc/qt-5.0/qtwebkit/qtwebkit-index.html