According to the docstring: font-menu-this-frame-only-p' is a variable declared in Lisp. -- loaded from "/usr/local/lib/xemacs-21.0/lisp/auto-autoloads" *If non-nil, then changing the default font from the font menu will only affect one frame instead of all frames. This variable gets set by the menu item Options/Frame Appearance/Frame-Local font menu But, at least for me, on XEmacs 21.0 "Poitou" it doesn't work - using the font menu changes the fonts in ALL frames, regardless of the setting of font-menu-this-frame-only-p Y'all probably know about this already - I'm well aware that there are lots of outstanding issues re: fonts and the options menu. I'll try to work on a fix, but would appreciate guidance from somebody who understands Customize a little better than I do.