Aristo is an open source UI distributed as part of the Cappuccino Web Application Framework and specifically designed for the cross platform challenges applications face today.

Aristo began as a collaborative effort by 280 North, Inc. and Sofa and was released under the Creative Commons Attribution Share-Alike License. Today it is maintained by the Cappuccino Project.

You can read the license here: http://creativecommons.org/licenses/by-sa/3.0/us/.

You can find out more about Aristo here.