Qt Quick and its related, declarative markup language, QML, are both relative newcomers to the Qt application framework, and offer tools for rapid, modern UX/UI design. While sharing all the power of Qt, Qt Quick provides everything needed to create rich applications with dynamic user interfaces. This richness comes from features such as animations, transitions, and visual effects (including particle and shader effects) being all native in Qt Quick.
A JSON-inspired language within the Qt framework, QML is Lintel's go-to for rich desktop applications. It allows us to create building blocks by declaring them and reusing those elements later.
Ultimately, Qt Quick / QML means a faster, smoother user experience within your application.