mvvmfx is an open-source framework to implement JavaFX applications following the MVVM (Model-View-ViewModel) pattern.
From the mvvmFX home page:
MvvmFX is an application framework which provides you necessary components to implement the Model-View-ViewModel (MVVM) pattern with JavaFX.
The home page contains links to downloads, tutorials, documentation, source code and a bug tracker. Note that the framework is considered to be feature complete.