The best is, I wrote a mail to him and he said, he downloaded the site design from a free template website.
But look what I found in his source code:
<!-- Mirrored from www.pellesc.de/ by HTTrack Website Copier/3.x [XR&CO'2008], Sun, 15 Nov 2009 05:44:44 GMT -->
Some people are really strange...
But his "cool Web Browser" is also only a really bad way to use the mozilla components. Didn't they release everything under GPL?