concrete5 is an open source content management system (CMS) for publishing content on the World Wide Web and intranets.
Concrete5 was designed for ease of use, for users with a minimum of technical skills. It enables users to edit site content directly from the page.
It provides version management for every page, similar to wiki software, another type of web site development software. concrete5 allows users to edit images through an embedded editor on the page
More information on : http://www.concrete5.org/