ShoutCMS

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PyroCMS

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.

With Contentstack, content and marketing teams are able to publish content with a much higher frequency than ever before. Contentstack brings business and technology teams closer together by providing a personalized, omnichannel experience with a visual editor alongside content scheduling and publishing management tools.

Craft CMS is a flexible, user-friendly CMS for creating custom digital experiences on the web and beyond. Craft is designed from the ground up to empoer the entire creative process. From the user-friendly interface to the completely customizable back end, everything you interact with is designed to just make sense. With Craft your content comes first. No more trying to make your content work within the confines of the CMS.

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.

WordPress powers roughly 30% of all web pages online. It's a free and open source CMS designed and developed for self-hosted publishing by Automattic, Inc. The software is written in PHP and utilize either MySQL or MariaDB as a database, and is compatible with most web hosts. Wordpress includes a plugin architecture and a templating system that can be used to extend and customize your website. These are commonly known as WordPress plugins and WordPress themes and make up a whole open source and commercial eco-system where anyone is free to create products for the platform. 

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.