NetBeans opens a web browser with the index page of our Grails application if we run the application. If we don't want this behaviour or if we turned it off, but want to turn it on again, we right-click on the project in the Project window and select Properties. We click on the General Settings node and we check or uncheck Display Browser on Run.
We close the dialog window by clicking on the OK button. Next time when we run the Grails application the web browser will be shown or not depending on the choice we made in the dialog window.