I'm trying to develop a dev website for small business and am looking for a GUI HTML Editor that is easy to access for people that can't code or aren't familiar with HTML/CSS/JS. Is there any recommendation of an open-source CMS-like software/application that allows users to develop a website with a GUI?

The company is trying to stay away from CMS due to it's restrictions, however the workers I'm working for web-development is rather focused on marketing and content managing, (thus they aren't comfortable with programming) but the boss still want them to be able to edit the website a bit.

The boss has also told me that he has a Adobe Creative Cloud subscription and has an account for Dreamweaver CC. I was also wondering if that is a good application to use for web development and is a good GUI HTML editor?