I needed something. . . . easy to create themes; easy to reverse engineer into existing sites; easy interface for users; in-context editing (the ability to edit website content directly on the page, rather than in an administrative interface or using editing software).
Based on PHP it is targetted at doing right by developers and users. Neither suffers at the expense of the other.
The team at concrete5 continue the mission to keep things easy, flexible and robust.
Don't just listen to my spin. . .
2011 Open Source CMS Market Share Report
Concrete5 had the best 12 month period of any CMS in this survey.
Though Concrete5 still lags the Big 3 in terms of total market share, no other system we looked at came close to showing the growth seen by Concrete5. The fact that the system also performed well in the 2010 Report leads us to the conclusion that Concrete5 is a contender, and bears close watch.