I am surprised that no one has mentioned ExpressionEngine . It's not free (maybe why), but in PHP, there is a thriving community, many plugins (good ones are not free, but the php programmer may consider this a possible source of income). It is built on the basis of PHP - Code Ignitor.
Now I play with Concrete5 - I really like editing on the page. It is based on MVC, extensible. Easier (yet) than EE, EE is easy to use and template is easier than Drupal. Drupal is surprisingly powerful, but as others have noted, there is a steep learning curve. Even if you are php whiz, you need to learn the "Drupal path" to the template, encode, that's all, it is really very important. However, Drupal can really do something, and has some very reliable and highly professional sites and a huge community.
mahalie
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