It's FOSS - https://itsfoss.com/open-source-cms/
Brief: Looking for a free and open source website creation tool? We have created a list of 12 open source CMS that you can use for various kind of websites.
A CMS (Content Management System) is what lets us manage the content or information on a webpage. However, it is capable of a lot of other things than just “managing the content”. And, the root cause for the rapid evolution and extensibility of CMS’ would definitely be – “Open Source CMS initiatives”.
The more open source CMSs surfaced, the more extensible they became. Well, some open source CMSs focused on