Pico – Flat-File CMS
Pico is an open source CMS application that is capable of very few things. It uses flat-files as the database and built with PHP. Simply, there is no setup and the app works instantly.
Koken – An Impressive Free CMS For Creative Websites
Koken is a free and self-hosted CMS (PHP-MySQL) that is focused on building websites where portfolio/gallery is in the core (like designer or photographer sites).
Textpattern – Open Source & Full-Featured CMS
Textpattern is an open source content management system, built with PHP/MySQL, that offers a flexible usage for designers, publishers/bloggers and end-users.
