how to input diacritic characters

I always used vim (for example, "Ctrl-K" ":" "u" for "ü"), but now I found a way to input such characters into any application, using the core feature of X11/xorg. The explanation and the table are here: "ISO-8859-1 compose keystrokes in Linux" (thanks Andrew Daviel).

Reminder for myself: on my system, it's enough to add "compose:ralt" to the option "XkbOptions" in "xorg.conf" and use "Alt Gr" key.

Categories: linux