SlackBuildsOrg/desktop/dunst

dunst (notification daemon)

Dunst is a lightweight replacement for the notification-daemons provided
by most desktop environments. It's very customizable, doesn't depend
on any toolkits and therefore fits in those windowmanager centric setups
we all love to customize to perfection.

Configuration:

To customize dunst you have to copy config file from /etc/xdg/dunst to
~/.config/dunst/dunstrc, then modify it to your liking.