According to this post on the Zend Developer Zone (and the original post by Greb Murray), the jMaki project has announced that they will support PHP as a part of their Ajax framework.

am proud to announce that jMaki now has a server runtime that fully supports jMaki for PHP 5. This is in addition to JSP, JSF, and Phobos.

The jMaki project is an Ajax framework that gives the developer some lightweight, reusable widgets either they can make or that can be inherited from something like the Dojo toolkit, Yahoo UI, Scriptaculous, and many other libraries. This new PHP integration makes it as easy as a simple PHP call to integrate it into your application.

Check out Greg's blog entry for more details and an example of how to use this new functionality.