According to this post on PHPBuilder.com today, there's a new PHP-based Ajax-enabled site builder that's been released - Drag Drop Site Creator.

SQLFusion recently announced the release of its online site building application, built with "AJAX" technology. This online web site builder, called Drag Drop Site Creator, is intended primarily for web hosting companies, which offer Drag Drop Site Creator as an additional service to their hosting customers.

The software is entirely server-side, and uses the Ajax to work like a WYSIWYG editor on the user's local machine. You can even point/click/drag your way to any layout you want...