If like me your head is spinning from all the announcements of proprietary "AJAX killers" out there then you probably were still too busy trying to digest Silverlight to even have heard that Sun's announced it's own "AJAX killer" and Flash competitor named Java FX.

Don Park has a good post which serves as a good starting point to grok the meat of this announcement titled Inside JavaFX where he writes

So what is JavaFX? This is what it looks like:

import javafx.ui.*;

Frame {
  title: "Hello World JavaFX"
  width: 20
  height: 50
  content: Label {
    text: "Hello World"
  }
  visible: true
}

As you can see, JavaFX script (*.fx) is basically JSON-like version of XAML which can be either compiled into Java bytecode or run as is using a java-based JavaFX player. Since JavaFX is just java, it can run as applets in browsers, midlets on mobiles, and applications on WebStart.

Sam Ruby has a good follow up to Don's post titled JavaFX Script where he describes some of the innovations and shortcomings of the platform he has noticed in his initial observations.

It looks like Web developers are getting spoiled for choice this summer; Sun vs. Microsoft vs. Adobe vs. Web Standards.