OK, maybe I\'m dumb/blind, but in the docs it says \"rebuild and restart the server.\" But I don\'t see a button to do this anywhere. Or from any contextual menu. And I can\'t f
The previous answer wasn't cutting the cheese for me. Upon first starting App Engine, the red square would be available above the text entry area. If I then clicked the run button again, then red square would go away and the console for the previous launch would be replaced by the console for the new launch. To manually stop the App Engine server, you can kill it from the terminal: http://geekbrigade.wordpress.com/2009/02/26/how-to-find-and-kill-a-process-that-is-using-a-particular-port-in-ubuntu/ In short, "sudo netstat -lpn |grep :8888" and kill the service by process ID.
Strangely, adding Google Web Toolkit to the project made my App Engine launch show up in the Development Mode pane, where it could be easily be killed or restarted.