TYPO3 is a free Open Source content management system for enterprise purposes
on the web and in intranets. It offers full flexibility and extendability while
featuring an accomplished set of ready-made interfaces, functions and modules.

The stable LTS release (for old projects)
This version is the Long Term Support release. It can be used for existing
projects, and will get full support (bug fixes and security fixes) until April
2014. Important and security related fixes will be provided until March 2015.

WWW: http://typo3.org/