HTML_AJAX
Here’s one library that’s pretty nice: PAJAJ - they have some slick demos.
HTML_AJAX had its first PEAR release today. Its the same version as was voted on so there is no new code but you can use the PEAR installer to get it.
Once you have it installed you’ll find the examples in the docs dir to be quite helpful, on my server thats /usr/share/pear/docs/HTML_AJAX/examples. These examples are also available online: run, view code.
I’ve started a basic website for the project, it includes a development roadmap, so if you want to help out, or just want to know whats happening next thats a great place to start.