I wanted a free hosting solution for the project and also am a big fan of the Groovy programming language (my Java background showing) So, I thought I'd try using Gaelyk on Google App Engine. I first pushed a test version several months ago, but I've just pushed a new version to iui-js.appspot.com and also checked in my work-in-progress to revision control.
I've also created a wiki page called iUI on Google App Engine. The wiki page has (hastily-written) draft instructions on "How I Did It" -- as well as a to do list. Please let me know if you have any suggestions on the to do list.