concrete5 is a free and open
source PHP built content management system for content on the web and also for
intranets. Its emphasis is on management and editing with minimal technical
skills and with an embedded editor allows most editing to be done directly from
a page, rather than through an entirely separate interface or editor. It
features integrated server caching, supports OpenID, version control, and SEO.
As with most open source content management systems, its content management
functionality can be augmented with many possible addons or via the developer
API.
Online
magazines and newspapers are the ideal target of concrete5's capabilities
though many other sites can be made and managed as well. concrete5 is touted as
being both developer and DIY friendly. Marketplace content to extend features
are both free and not free, so cost of implementation will vary.