jQuery plugin to create user interfaces using Ajax, XML and XSLT transformations on the client-side. The project is about both the client side and the server side, so the server must send and receive appropiate messages.
Have a look at test_module/cp.php. This a PHP server-side script but nothing prevents you from using another language in the server: Python, Ruby, Java... as long as you send the client engine the expected XML/XSLT messages through Ajax.
This project was conceived some 7 years ago and I don't know if it works well on modern browsers, but I have checked with a current Firefox and it works as a charm.
Under the the directory test_module there is a handful of PHP, XML and XSLT files to test this project out, you only need to drop jQuery and you are ready to go. The project is tested with jQuery 1.3.2 but maybe it is worth trying the current -or a modern- version.