Content Management Systems
There are many good quality content management systems available. Some are commercial and some are free. The big three popular choices are Joomla, WordPress and Drupal. There is also a long list of other free well known content management systems; such as Modx, Xoops and CMS Made Simple. One the other hand, there are choices for a commercial CMS like DotNetNuke and Expression Engine. Nobody ever said you have to use just one and stick with it. However, learning any system very thoroughly does take some time, even without the upgrade and new versions factoring into the equation.