bBlog was started as a project by Eaden McKee to see how far the Smarty templating system could go toward supporting a full fledged blogging and content management framework. From the beginning, the goal was to keep the system centered on the template concept, and make new features fit into the modular plugin framework that Smarty lays out.
bBlog builds on the tradition and concepts of b2, Wordpress and other PHP blog software, but is not based on the same code. It is available under the GPL, which means it's free to use, and you are free to modify and redistribute it.
Try out bBlog! NEW
Thanks to the folks at opensourcecms.com, you can try out bBlog, including the admin interface here.