FireCMS

vs

SilverStripe

Primo is an all-in-one IDE, CMS, component library, and static site generator. With Primo you can build sites faster, add and manage content more easily, create an actual, usable component library, and publish a fast, secure, cheaply-hosted static site.

With Automad you can manage content easier than ever. Automad is a file-based content management and template engine that allow you to create fast website without the need of a database. Instead all content is stored in human readable text files which makes it easy to put a whole site under version control with Git. The elegant admin panel provided by Automad includes a block editor and the in-page editing capability. You can also extend the core of Automad by creating your own packages or making use of the once already created by the community.

Backdrop is a full-featured content management system written in PHP. The Backdrop CMS allows non-technical users to manage a wide variety of content. It can be used to create all kinds of websites including blogs, image galleries, social networks, intranets, and more.

Joomla is a free and open-source content management system written in PHP. The CMS is built entirely by volunteers from all over the world and has a strong community that provide educational resources, and extensions. 

Django CMS is a free and open-source content management system build on the Python web framework Django. With Django CMS, you can create your own website or blog in a matter of minutes which is easy to maintain far into the future. If you are a developer utilizing the Django framework you can integrate Django CMS into an exiting Django application and take advantage of it's publishing and editing features.

CMS Made Simple is a free and open-source content management system that offers an easy to use interface for end users, while maintaining a powerful backend for developers. CMS Made Simple is written in PHP and got an extensive API and custom modules. The CMS also utilize the Smarty templating engine that can be used to customize sites with HTML, CSS and PHP.