Bootstrap for JavaFX.
DesktopPaneFX is a JavaFX version of Swing’s JDesktopPane which can be used as a container for individual "child" similar to JInternalFrames.
Ikonli provides icon packs that can be used in Java applications. Currently Swing and JavaFX UI toolkits are supported.
JSilhouette provides additional shapes for Java applications. Currently JavaFX is supported.