Thunder is a web-based, open-source, Drupal 8-based Content Management System for professional publishers. Publishers, industry partners, and developers can leverage worldwide community collaboration to implement Thunder, build custom extensions and share them with the Coalition to further enhance the system and innovate faster and cheaper together.
Thunder was released in March 2016 by Hubert Burda Media. Since then, Burda has migrated many of its brands to Thunder (e.g. instyle.de, bunte.de,...). And the idea of an open-source CMS was also embraced eagerly by publishers worldwide: Many other publishers have started their own Thunder projects.
Find out more about Thunder at thunder.org