bBlog is a powerful, elegant personal publishing system written in PHP and released as free, Open Source software under the GPL. It is a flexible but simple way to blog that works for blogging beginners, and can grow into a more advanced user's needs.
bBlog is used by thousands of bloggers world wide and has not only the features you would expect from a modern blogging system, but also advanced capabilities including advanced comment spam prevention and threaded comments. Perhaps bBlog's most distinctive feature is that it is built around a templating system called Smarty, which makes customizing your blog as easy as editing any web page, no programming skills required.