WorkSimple is exactly that. A simple, easy to use blogging system with a blog module, ad & theme system, calendar and login/register features written in PHP.
It also includes a effortless installer so WorkSimple can be implemented on any website within minutes (Or even seconds!). A complete tutorial is available here: http://2500mhz.info/node/24
WorkSimple uses a flatfile database, so no MySQL database is required, thus making it even easier and faster to install & use.
WorkSimple is style-able via CSS. New themes can be uploaded and used instantly. See the Themes page for themes.
A demo is available here: http://2500mhz.info/cms/
For support, feel free to post comments. (If there are more comments to handle, I will create a forum) For any other contact or feedback, use the Contact/Feedback page under Secondary links.
This work is licensed under a Creative Commons Attribution 3.0 Unported License.
Problem
Went to check this out and found your demo has been hacked...
Ah thanks, someone posted
Ah thanks, someone posted HTML code in the tagline making to execute.