plone.org

Plone is a free and open source content management system. It can be used for any kind of website, including blogs, internet sites, webshops and internal websites. It is also well positioned to be used as a document publishing system and groupware collaboration tool. The strengths of Plone are its flexible and adaptable workflow, very good security, extensibility, high usability and flexibility.

LINK: https://plone.org/