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 latest stable release (for new and existing projects)
This version is the current stable release. It is recommended for existing
projects and will get full support (bug fixes and security fixes) until October
2013, but will get security fixes and important bugfixes until October 2014.

WWW: http://typo3.org/