Batflat - Lightweight, fast, easy, and free CMS.
Rubedo - Rubedo is an open source big data CMS & E-commerce with Behavioral targeting.
Wagtail CMS - Django-based Content Management System.
dotCMS - Java-based content management system
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.
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.