244073 Simple Forum

I would like a simple forum designed in PHP. I prefer a clean style like CL NOT something like phpBB. The code should be clean and scalable so it can be easily modified. I prefer developers who use classes and methods not procedural style. Please respond only if you have built forums before as you understand the basic requirements from a user and administration standpoint. Forums I like are digg style and CL style where users can rate each post (+/-) Send links of the forums you built. A demo would be appreciated. It is also important that posts be SEO friendly.