User:Zhaofeng Li/SummaryGuard

This script forces you to provide an edit summary when editing. It also shows the length of the edit summary above the text box, which changes its colour when the summary becomes too lengthy.

common.js
Install this script by adding this code to your common.js file: User:Zhaofeng Li/SummaryGuard.js

Greasemonkey
If you have Greasemonkey installed, click here to install this script on the browser. This also works if you are editing anonymously.