QML, the declarative language for designing UI-centric applications as part of Qt Quick, will also work for web-site design as part of a new KDE project.
QML is an important part to Qt Quick and Qt5 while now it can also be used for designing the user-interface side of web-sites. This isn't coming via an HTML5 back-end for Qt, like the GTK3 HTML5 back-end
QmlWeb has been a work in progress for a few years while now as of this week it's been accepted as a KDE project. QmlWeb isn't yet on a feature parity to the Qt5 implementation of QML, but it already supports most basic QML syntax and element types.
Those wanting more on this KDE QmlWeb project can find details and demos within this blog post
by Anton Kreuzkamp who has taken over as maintainer of the project.