Fx behaves well when another toolkit provides the event loop. For example, on the Mac, there is only one event loop thread per process and the JavaFX/Swing interop code does not attempt to create another one.

SWT is an apartment threaded toolkit and JavaFX and SWT can share the same apartment, greatly simplifying interop. Adding the property (which will not be API) will enable this. Note that I am not proposing that the SWT interop code be part of Presidio. Rather, I'd like the property to be in the release so that we can make the interop code available (should we chose to do so) without a modified version of Fx 2.0.