Note that you might consider using HT-SIMPLE-AJAX, which is is a heavily simplified version of HT-AJAX that lacks some features but works with current versions (> 1.1) of Hunchentoot.
Basically it allows 'exporting' of your lisp functions so that they can be easily called from the Javascript code on your web page. The details of the data transfer can be handled by different backends, or as we'll call them 'AJAX processors'. At the moment three such processors are supported: one simple, built-in, that generates code inside the web page and does not require external libraries. The others are using a javascript library, such as Lokris or Prototype.
The documentation for HT-AJAX library including a small tutorial can be found here.
HT-AJAX is written in Common Lisp and aims to be portable across implementations as well as web browsers. Patches, bug reports, requests and comments are welcome.
The package has found a new home at common-lisp.net, as the author could not be reached anymore. If you are the author, please send email to rt at common dash lisp dot net so that we can get in touch.
Version 0.0.6 (2007-02-20) added support for Yahoo UI library, Dojo Toolkit, "virtual .js file" feature, option to compress the generated Javascript, error and success callbacks, returning complex objects to Javascript with JSON.