Chyrp is a blogging engine designed to be very lightweight while retaining functionality. It is driven by PHP and MySQL (with some AJAX thrown in), and has a pimpin’ theme and module engine, so you can personalize it however you want.
FreePHPBlogSoftware is free blogging software powered by PHP scripting and a MySQL database. The software is released under the GPL license. The software is feature loaded, very easy to install, simple to customize, and a breeze to use!