We show how the features of modern integrated functional logic programming languages can be exploited to implement graphical user interfaces (GUIs) in a high-level declarative style. For this purpose, we have developed a GUI library in Curry, a multi-paradigm language amalgamating functional, logic, and concurrent programming principles. The functional features of Curry are exploited to define the graphical structure of an interface and to implement new graphical abstractions, and the logic features of Curry are used to specify the logical dependencies of an interface. Moreover, the concurrent and distributed features of Curry support the easy implementation of GUIs to distributed systems.