Makes easier to type UNICODE, into Geany.
http://www.geany.org/
For example, after you have typed 2203, into Geany, press Ctrl+Right Alt+y, and 2203 is replaced with ∃.
To replace at most 3 hex digits left of cursor, press Ctrl+Right Alt+o. This makes possible typing modifiers, to letter e, that would otherwise be considered a hex digit. For example, type e301, and next press Ctrl+Right Alt+o, and e301 is replaced with é.
Last you may type things like 1d4ae, and press...