How to install
Firefox Greasemonkey and Safari GreaseKit: just click on nice-alert.user.js
Quote from Jef Raskin
The information-theoretic efficiency E of an interface is defined as the minimum amount of information necessary to do a task, divided by the amount of information that has to be supplied by the user. As is true of physical efficiency, E is at least 0 and is at most 1. Where no work is required for a task and no work is done, the efficiency is defined as 1.
— from “The Human Interface” by Jef Raskin, pages 84—85.