Please visit documentation pages.
Actual development code avaliable in develop branch.
You can find some binaries at DaD's project.
Now it's distributed as package of MSYS2 project. Type in the appropriate shell:
pacman -S mingw-w64-i686-osgQtQuick
pacman -S mingw-w64-x86_64-osgQtQuick
The osgQtQuick is now support all QtQuick render loop types. But if your application has problems on startup or resize the window, try to set a environment variable "QSG_RENDER_LOOP" to the value of "basic", "windows" or "threaded".