In the Applications library folders you find runnable apps with custom user interfaces tailored with the Application Builder to simplify solving a specific problem using COMSOL Multiphysics. To run an application, click the () Run Application button. If, instead, you want to explore how the application is constructed, click () Open. For applications in this folder, clicking the () Open PDF document button launches the PDF document that you can access from the running application. If no such document is available, this button is not activated. For further details, see the next section.