WordPress (WordPress.org) is a content management system (CMS) based on PHP and MySQL that is usually used with
the MySQL or MariaDB database servers but can also use the SQLite database engine.Features include a plugin architecture and a template system. It is most associated with blogging but supports other types of web content including more traditional mailing lists and forums, media galleries, and online stores.
Joomla is a free and open-source content management system (CMS) for publishing web content, developed by Open Source Matters, Inc. It is built on a model–view–controller web application framework that can be used independently of the CMS.
Joomla is written in PHP, uses object-oriented programming techniques (since version 1.5) and software design patterns, stores data in a MySQL, MS SQL (since version 2.5), or PostgreSQL (since version 3.0) database, and includes features such as page caching, RSS feeds, printable versions of pages, news flashes, blogs, search, and support for language internationalization.
Drupal also describes itself as a Web application framework.When compared with notable frameworks Drupal meets most of the generally accepted feature requirements for such web frameworks.
Drupal is a free and open-source content management framework written in PHP and distributed under the GNU General Public License.Drupal provides a back-end framework for at least 2.3% of all websites worldwide – ranging from personal blogs to corporate, political, and government sites.Systems also use Drupal for knowledge management and for business collaboration.
Squarespace is a private American company, based in New York City, that provides software as a service for website building and hosting. Its customers use pre-built website templates and drag and drop elements to create webpages.