Prevent mootools-core.js and mootools-more.js from loading

A lot of times when you build a Joomla website, you actually don't need the Mootools JavaScript library. To prevent mootools-core.js and mootools-more.js from being loaded, you can modify the Joomla core. However, ones you update Joomla, the changes might be overwritten.

To stop Mootools permanently from being loaded on your Joomla website just add the following code in the beginning of your Joomla template.

From http://www.joomlacheatsheet.com/blog