Drupal:

Drupal is considered among one of the most important free and open-source content management frameworks written in PHP and distributed under the GNU General Public License. It is used as a back-end framework for at least 2.1% of all websites worldwide. The standard release of Drupal is also known as Drupal Core. It mainly contains the basic features common to content management systems. Drupal is a cutting-edge platform that supports the latest technologies that the web has to offer.

WordPress:

WordPress is another free and open sources content management tool. It is also considered as a free and open source blogging tool, based on PHP and MySQL. It mainly runs on a web hosting service and the features include a plug-in architecture as well as a template system. As a open source CMS, WordPress is used by more than 18.9% of the top 10 million websites.

Magento:

Magento is an open source e-commerce web application that was launched under the name Bento. It was developed by Varien (now Magento, a division of eBay) with help from the programmers within the open source community. Magento was built using parts of the Zend Framework. It uses the entity-attribute-value (EAV) database model to store data.

Joomla:

Joomla is a free and open-source content management framework (CMS) which is mainly used for publishing web content. It is built on a model–view–controller web application framework that can be used independently of the CMS. Joomla is written in PHP and mainly uses object-oriented programming techniques, software design patterns.