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.
Sulu - Sulu is a content management platform based on Symfony, ideal for business websites and web-based software.
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.
Craft CMS - Content management system built on Yii PHP Framework
HubSpot Website Platform - HubSpot Website Platform is a content management system that enables marketers to build websites personalized for every visitor.
GeniXCMS - GeniXCMS is a Simple and Lightweight CMS and Framework. It's PHP Based CMS. Free and Opensource.