This is the correct place to ask GroovyFX questions.
Short answer: no, it does not support InternalFrame out of the box because the standard JavaFX API does not provide such widget.
However if there were to be a 3rd party JavaFX library that provides such widget then it would be fairly simple to register a custom factory on SceneGraphBuilder.
Sent from my primitive Tricorder
Not sure if I could post here on GroovyFX subject. Let me know otherwise,
I like to know if GroovyFX (or JavaFX) has support for InternalFrame type of window?