Open Source Software
SilverStripe
Silverstripe CMS is designed to be simple to learn and easy to use. Whether updating a page or publishing multiple pages on a large scale site. Give access to edit only specific areas of your site. Architected to safeguard your data from malicious activity or data-loss, even while scaling up complex sites.
TYPO3
TYPO3 is a free and open-source content management system written in PHP. The CMS is released under the GNU General Public License which makes it free to use for commerical and non-commercial projects alike. TYPO3 can run in most hosting environements and provides an easy way for people to write, manage and publish content online.
CppCMS
CppCMS is a free and open-source, high performance web development framework. CppCMS is not a content management system but rather a C++ web framework that has been designed for rapid web application development. Applications built with CppCMS are capable high loads with high request throughput.
Squidex
Squidex is 100% open source headless CMS, built by passionated developers. With Squidex both individuals and organizations can handle content for the new web with ease. Squidex modular platform allows users to create content APIs that can be consumed by any frontend framework or technology in a matter of minutes. The framework itself can also be extended and tweaked to suite individual use-cases. Squidex is provided as a fully open source software released and free of charge, for the self-hosted community edition. For organizations that want to get up and running fast, commercially hosted solutions are provided.
Kotti CMS
Kotti is a high-level, Pythonic web application framework. It includes an extensible Content Management System called the Kotti CMS, offering all the features you would expect from a modern CMS. Kotti is built on top of a number of best-of-breed software components, notably Pyramid, SQLAlchemy, and Twitter Bootstrap.
Wagtail
Wagtail is a free and open-source CMS built on-top of Django and Python. The CMS is built by developers and for developers and provides a configuration-less solution to content management. Wagtail plays nicely with your existing tech, especially if that stack utilze Python and the Django web framework. Wagtail can be installed as a package in existing Django application and extends the Django Admin to be more suited for content management.
Bootstrap CMS
CMS: Bootstrap - Opensource HTML/CSS/PHP and MySQL Content
Portal CMS
Portal CMS is a free and open source content management system with a powerful integrated page...