Which engine or framework should I use for co-editing?

Question

CMS

Hello!
It is necessary to solve the problem of joint editing of several articles,
the main criteria are:

• local accounts
  
• simple visual editor
  
• the ability to add an article by each participant
  
• the ability to edit any article by each participant
  

GoogleDocs is not suitable in this case, you need to make a separate resource and local accounts.
Perhaps there are frameworks or ready-made engines that implement this set of features.
Thank you.