[fuzztester]

No, I meant xlsfonts, as in the above man page I linked to.

It is a command line tool and can be used without a GUI. You can even query for the fonts on another X server's display (1). See this excerpt:

-display host:dpy This option specifies the X server to contact.

(1) - where the meaning of server and client is the reverse of that of traditional client server.

[zbuf]

Fair, I was thinking that because its not actually an X11 GUI (though it is X11 of course)

Its fun to query or set information on a remote. The same applies to xdpyinfo, xset, xrandr and many more support the -display option (if they don't then set the DISPLAY environment variable).