That sounds cool, but I don't know exactly what you mean... I think you might mean that you could create a Java applet front-end (using "Swing API"), and drive

That sounds cool, but I don't know exactly what you mean... I think you might mean that you could create a Java applet front-end (using "Swing API"), and drive something in GWT with that, if "GWT can handle Swing API input". But how would you create the Swing front-end? What would driving GWT do you? Please join the dots - doing this often reveals gaps that weren't clear before, so it's a good exercise. Taking another view: any Java app can be an applet (if you take care of things like access to the file system). Therefore, we already have then, since Eclipse and Netbeans can be an applet, and thus a web app. Theoretically, anyway. :-)