To start the Application Builder, click the Application Builder button () on the Home toolbar. The COMSOL Desktop then switches to display the toolbar for the Application Builder (or opens in a separate desktop window if you select the Use separate desktop window for Application Builder check box on the Application Builder page in the Preferences dialog box). When you have finished developing your application, you can run it by choosing Run Application from the File menu and pointing to the MPH-file for the application. You can also browse and run applications in The Main Window Branch. The figure below also shows how the applications can be accessed and run in the COMSOL Desktop. To return from the Application Builder to the Model Builder, click Model Builder on the Application Builder’s Home toolbar ().

The Application Builder window works analogously to the Model Builder with an application tree, context menus, toolbars, and Settings windows for every application tree node. The nodes in the application tree represent forms, events, methods, and other parts of the runnable application. You can add the graphical user interface (GUI) components (form objects) from the Form contextual ribbon toolbar and then position them interactively using the graphics tools in the Application Builder (see Working with Forms). You can also see a preview of what the form or entire application will look like when the application is run. The Application Builder is available for Microsoft Windows® operating system installations, but applications created using the Application Builder can be deployed and used on all operating systems, including running in a web browser together with COMSOL Server.