In recent development of MooTools, we've incorporated into the core a plugin that was once pushed under the table and neglected. The Hash is a powerful new way to extend objects just like you've always wanted...
Today we released MooTools version 1.11.
In this release we fixed a bunch of memory leaks issues, as well as some minor bugs around.
Other than some maintenance, we added the getText and setText Element methods, to help filling HTML Elements, Style tags and Script tags with text, and we added more details to the documentation.
This is a recommended update for all of you using MooTools 1.1.
If you want to, you can see the changelog in details.
So, go ahead and give it a try!