CMS

Hi all,
I want to create my own Content Menagment System (CMS). I want it to have a fully customizable menu, news system, custom themes and some simple features. I don’t want it to be a very difficult CMS like drupal, mambo etc. It must be as simple as it can be. Just to sell it for simple users which don’t want to pay a hell lot for the ownership of the code.

I’m still wondering though in what technology to make it. AJAX, or just simple xhtml+php+css.