A method and implementing computer system is provided in which a function or applet for example may be downloaded from a network server and graphical user interface (GUI) processor interprets a data stream consisting of GUI controls and attributes, and places the controls and attributes in a presentation space. In an exemplary embodiment, a web browser program loads an HTML (Hypertext Markup Language) from a GUI (Graphical User Interface) stream processor applet from a web server. The web browser then loads the GUI stream processor (GSP) from the web server and begins executing the GSP. The GSP then requests the GUI stream from the web server by opening a stream to a file, CGI (Common Gateway Interface) script or servlet on the server. The GSP then receives the GUI stream and assembles the user interface in the JAVA applet presentation space managed by the browser. The GSP may periodically update itself by repeating the last two steps.