Judging by the previous post, many of you are still interested in platforms for building your own CMS. I want to introduce you to the Ext JS library , also known as YUI-Ext . It has almost everything you need in CMS, work with tables and their editing, tree navigation with support for drag & drop and inline editing , work with XML and RSS . As for AJAX, you are given the opportunity to choose one of three popular libraries:
Yahoo! Ui utilities
Prototype + Scriptaculous
jQuery
I would also like to mention a few demonstration products made using this technology.