F3 had two constructs:

do { … }
do later { … }

If you read the F3 language resource (http://blogs.sun.com/chrisoliver/resource/f3.html) you’ll see that Chris didn’t think that “do” was quite right. And in fact, I’m not sure its terribly useful. Even in Swing I’ve hardly ever used do as opposed to do later.

I believe that “do later” in fact is also different from what I’ve proposed above because the body of the “do later” actually runs on an EDT — just at some later time. So this is the same as FX.deferAction in the current SDK. I’m not an expert on F3 though, so I could be wrong.

Also, notice this comment in the above mentioned document:

“Such code must only access Java objects (and those objects must handle their own thread synchronization, if necessary)”

So in F3 you still couldn’t access or create F3 objects in a background thread. In the approach I’m proposing, you can in fact create JavaFX objects off thread, but the compiler will make sure you don’t interact incorrectly with objects declared elsewhere.

Also, in F3 there wasn’t a full “Task” like API that backed the operation, so you couldn’t bind up to progress or other such things