Back in the day (around the turn of the century) I worked for a startup building a web application using Common Lisp. We used a framework called IMHO, which was developed in-house by a couple of the lead developers. IMHO seems to have been deprecated, per http://www.cliki.net/IMHO and the source code is nowhere to be found. I am still in touch with the authors, so maybe I can encourage them to make it more available.

Using Lisp for a web dev platform was pretty nice. I was a support engineer in those days and I always found it useful to be able to pull up a console and inspect the actual running sessions to debug problems in production.