TYPO3

TYPO3 is a free and open source Content Management Framework. It has an open API that allows you to extend the frontend (website) and/or backend (administration) functionality. TYPO3 is released under the GNU General Public License. It can run on several web servers, such as Apache, nginx or IIS, on top of many operating systems, among them Linux, Microsoft Windows, FreeBSD or macOS. The concept of extensions makes TYPO3 capable of being developed and used in almost any way you can imagine, either by using any of the many extensions which are available for download, or by writing your own.

TYPO3 was initially authored by Kasper Skårhøj and is now further developed by a community of contributors and the TYPO3 Core Development Team.