How to configure XKB to give you a compose button
Eric Dorland wonders how to enable the Compose key just using XKB. Personally, I use my caps lock key for that, and using
Option "XkbOptions" "compose:caps"
in /etc/X11/xorg.conf, that’s easy enough.
Other options are compose:ralt, compose:rwin, compose:menu and
compose:rctrl.