REDAXO is an open-source content management system written in PHP and built on a MySQL database. It structures a website through categories, content blocks, a media pool and add-ons that extend its functions. Editors and developers use it to build and maintain websites. It is delivered as software to be installed on the user's own web server rather than as a hosted service, and its source code is published on GitHub under the MIT licence.
The project is developed by the FriendsOfREDAXO community. According to the website footer, the operator is Yakamara Media GmbH & Co. KG in Frankfurt am Main, Germany. Because the software runs on infrastructure the organisation chooses, that choice determines where content is stored, and the website does not mention a vendor-operated cloud for customer data. For a European organisation, the German operator, the MIT licence and the option to self-host allow the full stack to stay under its own control.