This manual page documents briefly the GSMarkupBrowser.app utility.
This manual page was written for the Debian distribution (based on the program's README file) because the original program does not have a manual page.
GSMarkupBrowser.app is a GNUstep Renaissance utility that allows a developer to review the look and feel of a GUI based on its GNUstep Renaissance Markup Language file (gsmarkup for short.) This allows the designer to develop the layout without having to actually have working code to run the program.
Of course, the GUI is just for visual inspection -- it does not support any functional use of the application.
GNUstep Renaissance home page is at http://www.gnustep.it/Renaissance.