Concrete CMS - Concrete CMS is an open source content management system for teams. A website builder with built in tools make editing content easy.
Zimplit CMS - The easiest Open Source Content Management System for small web- and minisites
Mezzanine - An open source content management platform built using the Django framework.
BaferCMS - The fastest and the easiest way to edit content "in-place", while looking at the website.
PhpSQLiteCMS - phpSQLiteCMS - a simple & lightweight CMS
Nibbleblog - Nibbleblog is a powerful engine for creating blogs, all you need is PHP to work.