iWebkit

From the website :

iWebKit is a file package designed to help you create your own iPhone and iPod Touch compatible website or webapp. The kit is accessible to anyone even people without any html knowledge and is simple to understand thanks to the included tutorials. In a couple of minutes you will have created a full and profesional looking website.

iWebkit is licensed under GNU licence, it’s also available for WordPress, Drupal, iForum and Grails themes. You can try the demo here and download the package here.