Drupal - Drupal - the leading open-source CMS for ambitious digital experiences that reach your audience across multiple channels. Because we all have different needs, Drupal allows you to create a unique space in a world of cookie-cutter solutions.
WordPress - WordPress is web software you can use to create a beautiful website or blog. We like to say that WordPress is both free and priceless at the same time.
Plone - Plone CMS: Open Source Content Management — Plone.org
Joomla - Joomla! is the mobile-ready and user-friendly way to build your website. Choose from thousands of features and designs. Joomla! is free and open source.
Craft CMS - Content management system built on Yii PHP Framework
Statamic - Build better, easier to manage websites. Enjoy radical efficiency. It's everything you never knew you always wanted in a CMS.