Jack Slocum, author of YAHOO.Ext, has recently launched http://extjs.com/. Initially, I thought the site was a remake of his personal site http://jackslocum.com/ with a greater focus on his YUI extension library. However, upon closer inspection, the new website is dedicated to framework interoperability. And since this blog has a similar mission, I felt it worth mentioning. Anyway, Ext already works with YUI, jQuery, Prototype, and Scriptaculous.