TYPO3

TYPO3 is an open source PHP based content management system for building and managing websites. It uses a web server, PHP, and a database, and the backend is accessed through a supported browser. It is released under the GNU GPL.

It separates a streamlined core from optional extensions and exposes an open API for extending frontend and backend functionality. TYPO3 can run on Apache, nginx, or IIS, and on Linux, Microsoft Windows, FreeBSD, or macOS.

A directory of thousands of extensions adds features such as forms, multilingual content, and integrations without changing the core. TYPO3 is backed by the TYPO3 Association, a not-for-profit member association, together with a fully owned service company, and a dedicated security team handles advisories for the core and extensions.