Typo3 is one of the most used free CMS after JOOMLA.
It stands out for a high level of scalability especially in the area of user privileges. There is also a gigantic amount of 3rd party components (in Joomla termed
extensions) out there which let you configure TYPO3 for amost any possible solution.
Like Drupal TYPO3 is not for the faint hearted or those out for quick success. Therre is talk of a rather steep "learning curve" especially in the area of template design.
If you are out for a very flexible, but still powerful system you should consider TYPO3.
TYPO3 was "created" by the Danish Christian Kaspar Skarhoj.
The system used at our school was built on typo3.