GUI - Graphical User Interface
Abbreviation for Graphical User Interface; pronounced "GOOEY". A set of screen presentations and metaphors that utilize graphic elements such as icons in an attempt to make an operating system easier to use. Unlike classic UNIX and DOS, which feature a command line interface, the Windows and the Macintosh operating systems present graphical environments for input and output.
You can be used RTF TO XML Converter operated from a Graphics User Interface.
Read about RTF to XML feature.