My Video

and a few others have been poking at our widget layer for the past few weeks, looking at adding Qt support. There was an earlier attempt at a Qt backend, but it never really got maintained, and there wasn't much interest in it back then.
Recently, though, Qt has made great strides on embedded devices and with support for advanced graphics architectures (such as support for OpenGL and DirectX rendering), and might be a great way for us to get a feel for some of the problems we'll face in the future when we try to integrate 3D-accelerated rendering into Gecko. Folks at Nokia have contributed much of this code, since they're interested in experimenting with Qt as well. We've got the initial work available on a hg branch (off mozilla-central; our first experiment on big-project branches in the future hg world).