Abstract: A computer unit has a browser is assigned a web application program cache and a configuration data file that specifies the web application programs storable in the cache and loadable from the cache without using an on-line connection to a communication network, in order to execute the web application programs. Update data for the configuration data file is read-in over an interface, assigned to the computer unit, and updates the configuration data file. A device for operating an application portal is configured such that the web application programs are selectable via the application portal. The programs are to be stored in a web application program cache. The device generates update data regarding the web application programs for the configuration data file as a function of the web application programs that may be selected; and provides the update data for transfer to the interface of the computer unit.