Tidiness is a Mac app built around the HTML Tidy project and the W3C html validator. It can scan an entire website, using tidy or the W3C Markup Validation Service to check the html and (optionally) tidy to report on the accessibility of each page. It’s very early days and is under active development. It’s available here so that you can try it and comment. Please try Tidiness and if you have any problems or suggestions, please get in touch with us directly here