Nutshell is a lightweight framework for hosting Peanut applications. It is not, strictly speaking, a content management system. It requires an experienced web to design and maintain.
Nutshell is also installed as a component of the WordPress adaptation for Peanut. This allows you to use a view model without hosting it on a WordPress page. This is helpful for admin features and other pages. If the site is using a theme that conflicts with Bootstrap you may add peanut pages to the site using Nutshell.
You may want to style Nutshell pages to match your WordPress site's page design.